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Señors at Scale - Software Engineering & Tech Leadership

Dan Neciu

A software engineering podcast for senior developers, staff engineers, and tech leads who build and scale systems in production. Hosted by Neciu Dan, Señors @ Scale features deep, technical conversations with engineering leaders from companies like Google, AWS, Microsoft, Cloudflare, Datadog, and Snyk.

Every week, we sit down with Staff Engineers, Principal Engineers, and technical leaders to unpack the real challenges of frontend architecture, micro frontends, React and Vue at scale, design systems, security, reliability, and technical leadership. No fluff, no surface-level takes. Just hard-

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  • 24 episodes
  • weekly
  • Avg 51 min
  • English

Episodes 24

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  • S3 · E4
    September 27 · 52 min

    Performance at Scale with Ryan Townsend (Cloudflare) | Black Friday, Edge Caching, Cache Hit Ratios

    You can't optimize what you don't measure. So why do so many teams still guess? In this episode of Señors at Scale, I sit down with Ryan Townsend, Principal Product Manager for Performance at Cloudflare. Ryan has spent 20+ years building for the web and a decade as a CTO. He co-founded Shift Commerce, an enterprise-scale headless SaaS e-commerce platform built on Ruby on Rails that handled billions in yearly revenue. Before that, he was CTO of Matalan Direct, which grew out of one of Shopify's fastest-growing businesses. We talk about why "Rails doesn't scale" was always a myth and how learning Rails in 2005 felt like AI feels today. Ryan also explains how he learned to let go of the code as a leader, using guardrails, weekly demos, and T-shaped engineers. Then we get deep into performance: why real user data beats Lighthouse on your MacBook, how one "no performance impact" personalization script cost seconds at P90, and how Shift hit 99%+ cache hit ratios using inventory tiers and edge personalization. Key Topics: - Why "Rails doesn't scale" was always a myth - Resume-driven development and why startups over-hire CTOs - Why deep experience plus AI is a superpower, and the junior talent pipeline problem - Letting go of the code: guardrails, weekly demos, and async leadership - T-shaped engineers and spreading context across teams - Adopting Scrum properly, training with Jeff Sutherland, and removing impediments - Cutting CI from 40 minutes to 3 - Real user monitoring vs synthetic testing - The render-blocking personalization script that cost seconds at P90 - 99%+ cache hit ratios, inventory tiers, and personalizing cached pages at the edge - Preparing for Black Friday traffic spikes CONNECT WITH RYAN 💼 LinkedIn: https://www.linkedin.com/in/ryantownsend/ 🦋 Bluesky: https://bsky.app/profile/twnsnd.com 🐙 GitHub: https://github.com/ryantownsend 🌐 Website: https://twnsnd.com FOLLOW & SUBSCRIBE 🎙️ Podcast: https://neciudan.dev/senors-at-scale 📬 Newsletter: https://neciudan.dev/subscribe 💼 Dan's LinkedIn: https://www.linkedin.com/in/neciudan 💼 Señors at Scale LinkedIn: https://www.linkedin.com/company/senors-scale/ 📸 Señors at Scale Instagram: https://www.instagram.com/senorsatscale/ 📸 Dan's Instagram: https://www.instagram.com/neciudev ADDITIONAL RESOURCES 📘 The Phoenix Project by Gene Kim, Kevin Behr, and George Spafford ⚡ Cloudflare Speed docs: https://developers.cloudflare.com/speed/ 🐢 Ryan's slowest site in the world (web perf practice repo): https://github.com/ryantownsend/slowest-site-in-the-world #WebPerformance #Cloudflare #RubyOnRails #Ecommerce #CoreWebVitals #EngineeringLeadership #SeniorsAtScale 💬 What's the biggest performance win you've found by actually measuring instead of guessing?

  • S3 · E3
    September 20 · 55 min

    Design Systems at Scale with Szymon Chudy (Netflix) | Hawkins, Paved Roads, AI Migrations

    What does it take to run a design system that 2,000+ applications depend on, when every team is free to walk away from it? a Software Engineer on Netflix's Hawkins team, which uses the design system In this episode of Señors at Scale, Dan sits down with Szymon Chudy, Software Engineer at Netflix on the Hawkins team, the design system used by thousands of engineers across Netflix's internal tools. Before Netflix, Szymon grew from Senior to Staff Frontend Engineer at Lokalise, where he co-owned the design system and led frontend direction across teams. Before tech, he was a professional guitarist with over a thousand concerts and two platinum albums. Szymon explains why he sees a design system as enablement rather than a component library, why he believes the source of truth lives in code and not in Figma, and how Netflix's "freedom and responsibility" culture forces the Hawkins team to think like a product team that has to earn adoption. We get into the UI paved road, shipping codemods and AI skills with every breaking change, running an alpha, beta and GA release across thousands of apps, and what an on-call incident looks like for a design system. We also talk about when you should not build a design system, what a visual refresh really involves under the hood, and whether the Netflix culture from No Rules Rules holds up from the inside, including informed captains, farming for dissent and the keeper test. Key Topics: - What a design system really is: enablement, not just components - Source of truth: Figma, code, or a separate component definition - Why markdown specs and LLMs don't solve the determinism problem - Hawkins Consumer vs Hawkins Professional at Netflix - Design police vs full freedom, and the case for a paved road in the AI era - Why design systems are slower than product, and why that's a feature - "Legal hacking": letting teams diverge with clear boundaries - Shipping skills, MCPs and context so agents can use your design system - Adoption rate as the success metric - Codemods, AI skills and human in the loop for major migrations - Alpha, beta, GA: releasing breaking changes to thousands of apps - On call for a design system: what counts as an incident - You may not need a design system - Netflix culture: freedom and responsibility, informed captains, the keeper test 🔗 FOLLOW SZYMON 💼 LinkedIn: https://www.linkedin.com/in/szymonchudy/ 🐦 X/Twitter: https://x.com/szymonchudy 🦋 Bluesky: https://bsky.app/profile/chudy.me 🌐 Website: https://chudy.me 🎙️ FOLLOW & SUBSCRIBE 📸 Instagram: https://www.instagram.com/senorsatscale/ 📸 Instagram: https://www.instagram.com/neciudev 🎙 Podcast URL: https://neciudan.dev/senors-at-scale 📬 Newsletter: https://neciudan.dev/subscribe 💼 LinkedIn: https://www.linkedin.com/in/neciudan 💼 LinkedIn: https://www.linkedin.com/company/senors-scale/ 📚 ADDITIONAL RESOURCES - Szymon's blog: https://chudy.me/blog - Lenny's Podcast with Elizabeth Stone (Netflix CPTO) on systems thinkers: https://www.lennysnewsletter.com/p/netflix-cpto-on-ai-and-the-future - No Rules Rules by Reed Hastings and Erin Meyer - The Culture Map by Erin Meyer - Grokking Web Application Security by Malcolm McDonald - Grokking Algorithms by Aditya Bhargava - The Pelican Brief by John Grisham #DesignSystems #Netflix #Hawkins #Frontend #React #Figma #PlatformEngineering #DeveloperExperience #AIAgents #Codemods #WebDevelopment #SoftwareEngineering #SenorsAtScale

  • S3 · E2
    September 13 · 52 min

    Agentic Systems at Scale with Vilva Athiban (Omio) | MCP, Orchestration Agents, LLM Cost Optimization

    What does an agentic AI system look like when it has to work 100% of the time for millions of travelers, not just in a demo? Vilva Athiban is Lead AI Engineer at Omio, one of Europe's leading travel platforms. In June 2024, Omio picked him and one other engineer to start an AI team reporting directly to the CEO and CTO. He had no ML background. All he knew was how to call an LLM API. Since then he has built Omio's internal AI platform, the MCP integrations that connect agents to company systems, and Omio.ai, a consumer-facing agent product built entirely on MCP with no agent framework. In this episode Vilva walks through the full evolution of the architecture: LangChain, then LangGraph for control, then no framework at all. He explains the difference between supervisor and orchestration agents, why bigger models turned out cheaper than mini models at scale, how they cap tool calls and cache prompts to control cost, why guardrails ended up with the legal team, and why he thinks loop engineering will die in a few months. We also cover harnesses and context compaction, whether RAG is dead, how to pick models in 2026, fine-tuning, and what a JavaScript engineer should learn to move into AI. Key Topics: - From JavaScript engineer to Lead AI Engineer with no ML background - LangChain vs LangGraph, and why Omio's backend is now 100% MCP - Supervisor agents vs orchestration agents - Bigger models with medium thinking were cheaper than mini models - Capping tool calls, summarizing tool responses, prompt caching - Guardrails are subjective: the whale hunting debate - The agent is only as powerful as the tools you give it - What MCP is and why it replaced RAG for Omio - Harnesses, memory, and context compaction in Claude Code - Loop engineering: a sugar-coated while loop - How to choose models in 2026 (big, mini, nano) - Why fine-tuning is coming back in 2027 - Are developers cooked? The autocomplete that writes 15 files - How JavaScript engineers can become AI engineers - The token bubble, budgets, and the move to open source models CONNECT WITH VILVA 💼 LinkedIn: https://www.linkedin.com/in/vilvaathiban/ 🐦 X: https://x.com/vilvaathibanpb 🐙 GitHub: https://github.com/vilvaathibanpb 🌐 Website: https://www.vilvaathiban.com/ FOLLOW & SUBSCRIBE 🎙️ Podcast: https://neciudan.dev/senors-at-scale 📧 Newsletter: https://neciudan.dev/subscribe 💼 Dan on LinkedIn: https://www.linkedin.com/in/neciudan 💼 Señors at Scale on LinkedIn: https://www.linkedin.com/company/senors-scale/ 📸 Señors at Scale on Instagram: https://www.instagram.com/senorsatscale/ 📸 Dan on Instagram: https://www.instagram.com/neciudev ADDITIONAL RESOURCES - Anthropic Learn: https://www.anthropic.com/learn - Model Context Protocol: https://modelcontextprotocol.io - Omio: https://www.omio.com #AIEngineering #MCP #AgenticAI #LLM #LangChain #LangGraph #SoftwareEngineering #AIAgents 💬 Have you hit the point where a bigger model was cheaper than a mini model in production? Tell me in the comments.

  • S3 · E1
    September 7 · 1 hr 7 min

    Decentralized Social Media at Scale with Dan Abramov (Vercel) | AT Protocol, Bluesky, Redux, React

    What if every app's data lived in one shared, open database that no company owns? Dan Abramov says that future already exists, and he spent two years building it. Season 3 of Señors at Scale opens with one of the most recognizable names in frontend. Dan Abramov is the co-creator of Redux, spent nearly a decade on the React core team at Meta, writes overreacted.io, and spent the last couple of years as an engineer at Bluesky working on the app and the AT Protocol. He is now at Vercel working on Next.js. In this episode Dan explains AT Protocol from first principles: why it is a specification and not a framework, how it splits hosting from apps, why your followers are not your data, and why he thinks Mastodon is a feudal kingdom passing messages on horses. He walks through migrating his own hosting to Eurosky, what it costs to run your own data server, and where a developer should start building. Then we get into Next.js, Turbopack vs Vite, the React Compiler, and why the creator of Redux has not needed a state manager in five years. Key Topics: - What AT Protocol is and why it is being brought into the IETF - The "everything folder": one repository per user, shared across all apps - AT Proto vs Mastodon and why message passing between instances does not scale - How a post from someone with 10 million followers actually flows through the network - Hosting, relays, PLC identity and the three things in your "passport" - How the Bluesky app itself is built (Go backend, React Native web frontend) - How companies make money when users own their data - Migrating your data hosting to Eurosky and the paper cuts along the way - did:plc vs did:web and what happens if you lose your domain - Why followers, likes and reposts are just links between JSON records - Running your own PDS on a VPS or Cloudflare Workers for close to free - Getting started: PDSLS, Tap, Constellation and building without a backend - Apps Dan wants to see on AT Proto and why cloning existing products is not enough - Vercel, Next.js and what Dan wants to fix - Turbopack vs Vite and the "no bundling in dev" bet - React Compiler as fine grained reactivity - Redux as a to-do list: where state should actually live - Book recommendation: Terence Tao's Analysis I (and its Lean companion) CONNECT WITH DAN 🦋 Bluesky: https://bsky.app/profile/danabra.mov 🐙 GitHub: https://github.com/gaearon 🌐 Blog: https://overreacted.io 🌐 Website: https://danabra.mov FOLLOW & SUBSCRIBE 🎙️ Podcast: https://neciudan.dev/senors-at-scale 📧 Newsletter: https://neciudan.dev/subscribe 💼 Dan's LinkedIn: https://www.linkedin.com/in/neciudan 💼 Show LinkedIn: https://www.linkedin.com/company/senors-scale/ 📸 Show Instagram: https://www.instagram.com/senorsatscale/ 📸 Dan's Instagram: https://www.instagram.com/neciudev ADDITIONAL RESOURCES - AT Protocol: https://atproto.com - "There are no instances in AT Proto" (Dan's blog post): https://overreacted.io - PDSLS repository explorer: https://pdsls.dev - Tangled (GitHub on AT Proto): https://tangled.org - Terence Tao, Analysis I Lean companion: https://github.com/teorth/analysis #ATProtocol #Bluesky #DanAbramov #React #Redux #NextJS #Decentralized #OpenWeb #WebDevelopment #SoftwareEngineering #SeñorsAtScale 💬 Would you move your data hosting off Bluesky's default servers? Or does owning your own JSON not matter to you? Let me know below.

  • S2 · E27
    August 1 · 59 min

    Accessibility at Scale with Craig Abbott (TetraLogical) | WCAG, Screen Readers, Design Systems

    Your product passes every automated accessibility check. Does that mean anyone can actually use it? Craig Abbott is a Principal Accessibility Specialist at TetraLogical and the former Head of Accessibility at the UK's Department for Work and Pensions, one of the largest government departments in the country, where he built a dedicated accessibility practice from nothing and open sourced the DWP Accessibility Manual. He has over 15 years in user centred design, previously working as a designer and design manager, and has led accessibility work across the public sector and at Elastic. In this episode we get into what "sustainable accessibility" actually means, why culture is harder to change than capability, and how to stop accessibility from walking out the door when the one passionate person leaves. Craig breaks down his three C's framework (compliance, culture, capability), the screen reader testing stack he actually recommends, and what you can realistically automate in a CI pipeline with Playwright, Cucumber and Guidepup. We also get into the uncomfortable stuff. Automated tools only catch around 40% of issues. A page can pass WCAG with two pixel text and invisible links. And with 95.8% of the top million websites failing automated checks, the LLMs writing your front end code were trained on all of it. Craig is autistic and ADHD, and he closes on cognitive accessibility, the WCAG AAA gap, and why designing for neurodivergent users is still mostly ignored. Key Topics: - What sustainable accessibility means and why third party audits alone don't get you there - Building an accessibility practice from scratch inside a 100,000 person organisation - The three C's: compliance, culture and capability, and why culture is the hardest - Embedding accessibility so it survives when the champion leaves - JAWS vs NVDA vs VoiceOver vs TalkBack, and why the "worse" reader is the better test - Running screen readers in VMs and BrowserStack without expensive licences - Accessibility acceptance tests in CI with Playwright, Cucumber and Guidepup - Why compliant does not mean usable, with two pixel fonts and invisible links as proof - Shifting accessibility left into design and research, not throwing it at developers - Why you cannot detect screen reader users in your analytics - The three highest impact things: automated tools, keyboard only, structured content - Why CSS and design systems aren't opinionated enough - AI-generated front-end code and the 95.8% problem - Whether AI browsing replaces screen readers, and why LLM interfaces are inaccessible too - Designing for neurodivergence, WCAG AAA, and the COGA guidance CONNECT WITH CRAIG 💼 LinkedIn: https://www.linkedin.com/in/abbott567/ 🐦 X: https://x.com/abbott567 🦋 Bluesky: https://bsky.app/profile/craigabbott.bsky.social 🌐 Website: https://www.craigabbott.co.uk FOLLOW & SUBSCRIBE 🎙️ Podcast: https://neciudan.dev/senors-at-scale 📬 Newsletter: https://neciudan.dev/subscribe 💼 Dan's LinkedIn: https://www.linkedin.com/in/neciudan 🏢 Show LinkedIn: https://www.linkedin.com/company/senors-scale/ 📸 Show Instagram: https://www.instagram.com/senorsatscale/ 📸 Dan's Instagram: https://www.instagram.com/neciudev ADDITIONAL RESOURCES TetraLogical: https://tetralogical.com WebAIM Million report: https://webaim.org/projects/million/ W3C Cognitive Accessibility (COGA): https://www.w3.org/WAI/cognitive/ Guidepup: https://www.guidepup.dev/ axe-con: https://www.deque.com/axe-con/ #accessibility #a11y #webdevelopment #wcag #frontend #inclusivedesign #softwareengineering #neurodiversity #designsystems #senorsatscale 💬 Has your team ever shipped something fully compliant that users still couldn't use? Tell me about it in the comments.

  • July 26 · 42 min

    Versatility at Scale with Carmen Huidobro (CTO, Incredible Bee) | 17 Years Freelancing, Automation, Ethical AI

    Is versatility the skill that actually survives the AI shift? In this episode of Señors at Scale, I sit down with Carmen Huidobro, CTO at Incredible Bee in Vienna. Carmen has spent 17 years in tech, almost all of it freelancing, working across Objective-C, Ruby on Rails, the web, mobile, hardware, and even ABAP in an SAP consultancy. Along the way, she spent five years in developer relations and developer education, and now leads engineering on long-lived macOS products like Renamer. Her argument is that the debate about generalists versus specialists misses the point. What matters is being an expert at adapting: recognizing patterns, carrying solutions across stacks, and dropping into unfamiliar environments without bringing chaos with you. Niches are not going away, but the durable skill is the one that moves between them. We also get into the part most teams get wrong: how to ship AI without betraying the people who use your software. Carmen walks through adding a local LLM to a twenty-year-old Mac app using Mistral and a llama.cpp runtime, why the model downloads on demand instead of shipping in the binary, and why it is opt-in rather than opt-out. Plus, the refugee hackathon app she built in 2016 that the City of Vienna still runs today, why she will not take money from junior developers for bootcamps, and what she calls "white guy-driven development". Key Topics: - Why versatility beats both generalism and specialization - Seventeen years of freelancing across stacks, platforms, and industries - SAP, ABAP, and why niche expertise never disappears - Building an ethical AI toolkit: Mistral, llama.cpp, and on-device inference - Adding an LLM to a legacy macOS app without breaking user trust - Opt in over opt out, and why you should never take features away - Deciding what should be automated and what should not - Pushing back when investors demand AI in the product - Where2Help: the 2016 refugee hackathon project in Vienna still runs - Why the junior developer market broke and what bootcamps can still fix - Stop telling women they have imposter syndrome - What AI will never teach you about solving problems CONNECT WITH CARMEN 🌐 Website: https://carmenh.dev 🐦 X: https://x.com/hola_soy_milk 🐙 GitHub: https://github.com/hola-soy-milk 🐘 Mastodon: https://hola-soy-milk.online/ FOLLOW & SUBSCRIBE 🎙️ Podcast: https://neciudan.dev/senors-at-scale 📬 Newsletter: https://neciudan.dev/subscribe 💼 My LinkedIn: https://www.linkedin.com/in/neciudan 🏢 Show LinkedIn: https://www.linkedin.com/company/senors-scale/ 📸 Show Instagram: https://www.instagram.com/senorsatscale/ 📸 My Instagram: https://www.instagram.com/neciudev ADDITIONAL RESOURCES Incredible Bee: https://incrediblebee.com Bad Website Club: https://badwebsite.club Distribute Aid: https://distributeaid.org #Versatility #Freelancing #Automation #EthicalAI #LocalLLM #Mistral #macOS #OpenSource #SoftwareEngineering #CTO #Podcast #SenorsAtScale 💬 Are you betting on going deep or going wide right now? Tell me in the comments.

  • S2 · E25
    July 19 · 45 min

    CI/CD at Scale with Marko Gaćeša (Semaphore) | Semaphore, Product Engineering, Agent Native

    Is testing, not coding, the real bottleneck of the AI era? Marko Gaćeša is Head of Product at Semaphore, the agent native CI/CD platform built for coding agents: fast, affordable, enterprise-ready, and fully open source. A serial entrepreneur and technologist, Marko founded Dry Tools, served as Chief Product Officer at Alchemy Cloud, and has spent his career building high-quality software across domains such as medical equipment and industrial automation before entering the crowded CI/CD market. In this episode, Marko breaks down what it takes to build a product for developers: why flaky tests are the worst enemy of fast delivery, how SemAI uses skills and agents to automate everything from GitHub Actions migration to flaky test analysis, and why the future developer experience lives inside your coding agent, not in a browser tab. We also go deep on the product side: running experiments with feature flags, pricing a CI/CD platform when a "minute of CI" means something different everywhere, product-led growth versus B2B sales, and structuring lean product teams when your engineers are the domain experts. Key Topics: - What Semaphore does and why CI/CD matters - Testing is the biggest bottleneck in the age of coding agents - What "agent native" CI/CD really means - Flaky tests and how SemAI helps agents debug them - Migrating from GitHub Actions automatically - How Semaphore achieves faster and cheaper builds - Running product experiments on infrastructure tools - Pricing strategy in the CI/CD market - Should AI agents trigger deployments? - Product team structure in developer tools - Book recommendations for product-minded engineers CONNECT WITH MARKO & SEMAPHORE 💼 Marko on LinkedIn: https://www.linkedin.com/in/markogacesa/ 🌐 Semaphore: https://semaphore.io/ 🐦 Semaphore on X: https://x.com/semaphoreci 🐙 Semaphore on GitHub: https://github.com/semaphoreio 💼 Semaphore on LinkedIn: https://www.linkedin.com/company/semaphoreci FOLLOW & SUBSCRIBE 🎙️ Podcast: https://neciudan.dev/senors-at-scale 📬 Newsletter: https://neciudan.dev/subscribe 📸 Instagram: https://www.instagram.com/senorsatscale/ 📸 Dan's Instagram: https://www.instagram.com/neciudev 💼 Dan's LinkedIn: https://www.linkedin.com/in/neciudan 💼 Show LinkedIn: https://www.linkedin.com/company/senors-scale/ ADDITIONAL RESOURCES - Semaphore open source repo: https://github.com/semaphoreio/semaphore/ - Semaphore CI/CD benchmark: https://semaphore.io/semaphore-ci-cd-benchmark-performance-and-cost-analysis - Semaphore docs: https://docs.semaphore.io/ - Books mentioned: Hug Your Haters by Jay Baer, plus Inspired, Empowered, and Transformed by Marty Cagan and the Silicon Valley Product Group #CICD #Semaphore #ProductEngineering #AgentNative #DevTools #DeveloperExperience #AIAgents #SoftwareEngineering 💬 Would you let an AI agent trigger your production deployments? Tell us in the comments.

  • S2 · E24
    July 12 · 44 min

    AI Harness at Scale with Maxim Salnikov (Microsoft) | GitHub Copilot, Agent Ops, Context Engineering

    Everyone can buy the same GitHub Copilot licenses. So what actually makes a company AI native? In this episode of Señors at Scale, Dan Neciu sits down with Maxim Salnikov, AI Dev Tools Solution Engineer at Microsoft, where he leads AI native development enablement for over 100 enterprise customers of Microsoft and GitHub in Norway. Maxim has been building for the web since the late 90s and now spends his days inside real enterprise dev teams, watching how AI adoption succeeds and fails across finance, energy, agriculture, and pure software companies. Maxim breaks down why AI adoption is a change management problem, not a technology problem, and why buying licenses is the easy part. We get into the anatomy of an AI harness, the internal layer that ships with tools like Copilot and Claude Code, and the external layer that successful companies build on top for their own codebases. He also makes the case for two new job titles emerging inside dev teams: context engineers and agent ops. Key Topics: - Why startups outpace enterprises in AI adoption, and how to close the gap - Handling AI skeptics: why one bad experience in 2023 shouldn't be the final verdict - Code as a secondary artifact: the harness is what you actually build - Internal vs external harness layers, and how the VS Code team builds its own tools - Context engineers and agent ops: the new roles appearing in team topology - The AI superheroes anti-pattern and why it doesn't scale - Managing agent skills like dependencies with APM (Agent Package Manager) - How to become an AI native engineer: orchestration over one-to-one chat CONNECT WITH MAXIM 💼 LinkedIn: https://www.linkedin.com/in/webmax/ 🐦 X: https://x.com/webmaxru 🐙 GitHub: https://github.com/webmaxru 🌐 Sessionize: https://sessionize.com/maxim-salnikov/ FOLLOW & SUBSCRIBE 🎙️ Podcast: https://neciudan.dev/senors-at-scale 📬 Newsletter: https://neciudan.dev/subscribe 💼 Dan's LinkedIn: https://www.linkedin.com/in/neciudan 🏢 Show LinkedIn: https://www.linkedin.com/company/senors-scale/ 📸 Instagram: https://www.instagram.com/senorsatscale/ 📸 Dan's Instagram: https://www.instagram.com/neciudev ADDITIONAL RESOURCES 📖 Agentic SDLC Handbook (free book mentioned in the episode) 📦 APM (Agent Package Manager) #AINativeDevelopment #GitHubCopilot #ContextEngineering #AIHarness #SoftwareEngineering #Microsoft #AgenticAI #DeveloperProductivity 💬 Is your team building its own harness on top of AI dev tools, or running them out of the box? Drop a comment 👇

  • S2 · E19
    July 4 · 53 min

    URL State at Scale with François Best | nuqs, React, TypeScript

    What if your app's state didn't live in memory, but in the URL? François Best is a freelance web developer, open sourcer, and founder of 47ng, where he builds web applications with a privacy-first approach. He is the creator of nuqs, the type-safe search param state manager for React with over 10,000 GitHub stars, used by companies like Sentry, Supabase, Vercel, and Clerk. In this episode, François shares the full story of nuqs, from a woodworking calculator he built during the pandemic to a framework-agnostic library supporting Next.js, React Router, Remix, and TanStack. We dig into the internals: the async update queue, browser rate limits on the History API, throttling and debouncing, render count budgets, and the end-to-end test suite that keeps it all stable across frameworks. We also go beyond the library. François breaks down the recent npm supply chain attacks, explains how staged publishing and reproducible builds protect maintainers, shares how AI agents changed his workflow (including a Cypress to Playwright migration done by Claude Code on Christmas Day), and makes the case for running local AI models when your code can't leave the building. Key Topics: - What nuqs is and the origin story behind it - URL as the source of truth and the async scheduling engine - Browser rate limits, throttling, and debounce semantics - Framework adapters: Next.js, React Router, Remix, TanStack - End-to-end testing across frameworks and render count budgets - What state belongs in the URL (and what doesn't) - Hidden nuqs features: loaders, serializers, URL keys, standard schema - The npm supply chain attacks and how to defend as a maintainer - AI agents in open source: migrations, RFC prototyping, slop PRs - Local AI models for privacy-conscious companies CONNECT WITH FRANÇOIS 🐙 GitHub: https://github.com/franky47 🦋 Bluesky: https://bsky.app/profile/francoisbest.com 🌐 Website: https://francoisbest.com FOLLOW & SUBSCRIBE 🎙️ Podcast: https://neciudan.dev/senors-at-scale 📬 Newsletter: https://neciudan.dev/subscribe 📸 Instagram: https://www.instagram.com/senorsatscale/ 📸 Dan's Instagram: https://www.instagram.com/neciudev 💼 Dan's LinkedIn: https://www.linkedin.com/in/neciudan 💼 Show LinkedIn: https://www.linkedin.com/company/senors-scale/ ADDITIONAL RESOURCES - nuqs: https://nuqs.dev - nuqs on GitHub: https://github.com/47ng/nuqs - TkDodo's blog: https://tkdodo.eu/blog - Aurora Scharff's blog: https://aurorascharff.no #React #nuqs #TypeScript #URLState #NextJS #OpenSource #WebDevelopment #SoftwareEngineering #SenorsAtScale 💬 What state do you keep in the URL, and have you ever rolled your own search param sync? Tell us in the comments.

  • S2 · E22
    June 28 · 42 min

    WebMCP at Scale with Susanna Wong (Typeform, Google Developer Expert) | Browser AI, Offline Models, Agents

    What happens to frontend engineering when software stops being deterministic? In this episode of Señors at Scale, Dan Neciu sits down with Susanna Wong, Staff Software Engineer at Typeform and Google Developer Expert in Web Technologies since 2020. Susanna's path is anything but typical: she studied engineering in the US, spent close to seven years as an architect and computational designer at firms like Arup, then pivoted back into software, building Kedro and Kedro-Viz at QuantumBlack before moving into AI features at V7 and now Typeform. Susanna breaks down the shift from training your own ML models to building on top of LLMs, what Web AI and offline browser models really offer, and the cross-browser hurdles still blocking local-first AI. She also takes us inside Typeform's multi-agent system, how the team thinks about evals for non-deterministic features, and why WebMCP could change how all of us build websites. Key Topics: - From architecture and computational design to frontend AI - Building Kedro and Kedro-Viz at QuantumBlack - Why training your own models gave way to the LLM baseline - Web AI, offline models, and on-device inference - The cross-browser problem with local-first AI - Typeform's multi-agent system: LangChain, A2A, MCP tools - Evals as unit tests for non-deterministic AI features - Offline vs online evals and tracking drift in production - WebMCP: bringing the web to agents 💼 LinkedIn: https://www.linkedin.com/in/susanna-wong-london/ 🐦 X: https://x.com/studioswong 🌐 Talks: https://www.youtube.com/watch?v=JcLZGfXKk8c FOLLOW & SUBSCRIBE 🎙️ Podcast: https://neciudan.dev/senors-at-scale 📩 Newsletter: https://neciudan.dev/subscribe 💼 Show LinkedIn: https://www.linkedin.com/company/senors-scale/ 📸 Show Instagram: https://www.instagram.com/senorsatscale/ 👤 Dan's LinkedIn: https://www.linkedin.com/in/neciudan 📸 Dan's Instagram: https://www.instagram.com/neciudev ADDITIONAL RESOURCES - Kedro: https://kedro.org - WebMCP / React Paris talk on the agent web - Typeform AI: https://www.typeform.com #WebAI #WebMCP #SoftwareEngineering #Frontend #AIAgents #Evals #StaffEngineer #Typeform #MachineLearning #Podcast #SenorsAtScale 💬 Are you building with offline browser models yet, or still calling the API for everything? Let me know below.

  • S2 · E21
    June 21 · 47 min

    Newsletters at Scale with Sebastian Lorber (This Week in React) | RSS Curation, Paid Acquisition, React Server Components

    What does it actually take to run one of the biggest newsletters in the React ecosystem, week after week, for over six years? In this episode of Señors at Scale, Dan Neciu sits down with Sebastian Lorber, creator of This Week in React, the newsletter read by over 45,000 developers every week, and a core maintainer of Docusaurus at Meta. Sebastian has worked with React since late 2013, spent years as an independent consultant, and slowly turned a side project into his full indie hacker income. Sebastian pulls back the curtain on the entire operation: how a French newsletter aimed at landing consulting gigs became an English curation powerhouse, the exhaustive weekly workflow across 2,000 X profiles and 500+ RSS feeds, and the Gmail size limit that quietly shapes every issue. We get into the unglamorous economics too, why French sponsors couldn't make it sustainable, how he prices and manages four ad slots a week, and why click counts are far more misleading than most sponsors think. The conversation also covers the human side of curation: walking back mistakes with link proxies, staying friends with maintainers while breaking their unannounced work, the slow decline of social reach, and why he checks React feature flags before telling anyone a feature is "shipped." Plus a candid look at the recent TanStack compromise, trusted publishing, and why it gives a false sense of safety. Key Topics: - Starting a French newsletter to attract consulting clients - Pivoting to English and converting an X audience - The exhaustive weekly curation workflow (X lists, RSS, InnoReader) - The Gmail truncation limit and how it shapes each issue - Why French sponsors couldn't make it sustainable - Managing four sponsors a week with Sponsy - Why click metrics are misleading (Apple, corporate security scanners, UTM) - Paid acquisition on X, Instagram, Reddit and what actually converts - Treating subscribers like a stream, not a possession - Checking React flags before announcing features - React Server Components, the activity component, and Docusaurus - The TanStack compromise, trusted publishing, and NPM security GUEST LINKS 💼 LinkedIn: https://www.linkedin.com/in/sebastienlorber/ 🐦 X: https://x.com/sebastienlorber 🐙 GitHub: https://github.com/slorber 🌐 This Week in React: https://thisweekinreact.com/ FOLLOW & SUBSCRIBE 🎙️ Podcast: https://neciudan.dev/senors-at-scale 📨 Newsletter: https://neciudan.dev/subscribe 💼 Show LinkedIn: https://www.linkedin.com/company/senors-scale/ 📸 Instagram: https://www.instagram.com/senorsatscale/ 👤 My LinkedIn: https://www.linkedin.com/in/neciudan 📸 My Instagram: https://www.instagram.com/neciudev ADDITIONAL RESOURCES This Week in React: https://thisweekinreact.com/ Docusaurus: https://docusaurus.io/ Sponsy: https://getsponsy.com/ #ThisWeekInReact #Newsletter #ReactJS #Docusaurus #OpenSource #IndieHacker #ContentCuration #SoftwareEngineering #ReactServerComponents #NPMSecurity 💬 Do you still read tech newsletters, or has AI and social changed how you keep up with the ecosystem? Let me know in the comments.

  • S2 · E17
    June 14 · 50 min

    Monorepos at Scale with Santosh Yadav (Principal DevRel, CodeRabbit) | Nx, Module Federation, AI Code Review

    Poly repos were good when we needed separation. But in the age of AI, do we still need it? Santosh Yadav doesn't think so. In this episode of Señors at Scale, I sit down with Santosh Yadav, Principal Developer Advocate at CodeRabbit, Google Developer Expert for Angular, GitHub Star, Nx Champion, and Microsoft MVP. Santosh has spent years deep in the monorepo world, including leading the move to Module Federation and driving Nx adoption across 30+ teams during his time as a staff engineer at Celonis. We get into why monorepos are quietly becoming an AI superpower, how context changes everything when AI tools can read your dependency graph, and what it actually takes to migrate 20+ apps off polyrepos. Santosh also pulls back the curtain on CodeRabbit: how they handle context engineering for code review, why they run evals against 40+ models, their AI slop detector for open source, and how the team reacted when the big labs shipped their own code reviewers. Key Topics: - Becoming a GDE, GitHub Star, and Nx Champion (and what each actually gives you) - Migrating 20+ apps to Module Federation at Celonis - Monorepo vs Polyrepo in the age of AI - Why AI tools thrive on monorepo context - What Nx really is and when you need it - Inside CodeRabbit: context engineering, model evals, and the AI slop detector - Sponsoring open source with $1M+ in commitments - How startups survive when the big labs ship competing features GUEST LINKS 💼 LinkedIn: https://www.linkedin.com/in/santoshyadavdev/ 🐦 X: https://x.com/SantoshYadavDev 🐙 GitHub: https://github.com/santoshyadavdev 🌐 Website: https://www.santoshyadav.dev/ FOLLOW & SUBSCRIBE 🎙️ Podcast: https://neciudan.dev/senors-at-scale 📨 Newsletter: https://neciudan.dev/subscribe 💼 Show LinkedIn: https://www.linkedin.com/company/senors-scale/ 📸 Instagram: https://www.instagram.com/senorsatscale/ 👤 My LinkedIn: https://www.linkedin.com/in/neciudan 📸 My Instagram: https://www.instagram.com/neciudev ADDITIONAL RESOURCES CodeRabbit: https://www.coderabbit.ai/ Nx: https://nx.dev/ #Monorepo #Nx #ModuleFederation #AICodeReview #CodeRabbit #Angular #DeveloperExperience #OpenSource #SoftwareEngineering #StaffEngineer What's your take, are monorepos the right move in the age of AI, or is polyrepo still worth defending? 💬

  • S2 · E11
    June 7 · 44 min

    Routing at Scale with TanStack Router's Nicolas Beaussart | React Router Migration, Monorepos, PayFit

    What do you do when React Router v5 is blocking your React 18 upgrade, your frontend spans 25 repos, and you have 5 different micro frontend strategies running in the same app? In this episode of Señors at Scale, Dan Neciu sits down with Nicolas Beaussart-Hatchuel, Staff Engineer at PayFit and maintainer of TanStack Router. Nicolas shares the full story of migrating a 1.5 million-line codebase from React Router v5 to TanStack Router using the strangler pattern, without big-bang migrations and without stopping 18 engineers from shipping 15-20 PRs a day. We also dive into the origin story of TanStack Router, why PayFit killed micro frontends entirely and moved back to a single monorepo, how building the whole app at once saved 25MB of JavaScript, and why his MCP experiments performed worse than simply letting AI agents read the code. Plus: what it really takes to go from senior to staff engineer. Key Topics: - How Nicolas got into coding and his first iframe-based micro frontend migration - The origin story of TanStack Router and URL-as-state - Migrating 1.5M lines from React Router v5 to TanStack Router - The strangler pattern applied to frontend migrations - Faking React Router providers to sync two routers on one URL - Consolidating 25 repos into one monorepo - Secret dependencies, Yarn v1 pain, and standardizing on Vite - Why dropping per-library builds saved 25MB of JavaScript - TypeScript Go in editors and its RAM cost - MCP servers vs agents reading code directly - Internal DevRel: winning engineers over with social proof - Going from senior to staff: system design and finding problems worth solving - What's next: TanStack Start v1 and parallel routes Connect with Nicolas: 💼 LinkedIn: https://www.linkedin.com/in/beaussan/ 🐦 X: https://x.com/beaussan 🐙 GitHub: https://github.com/beaussan 🌐 Website: https://beaussan.io FOLLOW & SUBSCRIBE: 🎙️ Podcast: https://neciudan.dev/senors-at-scale 📬 Newsletter: https://neciudan.dev/subscribe 💼 Dan's LinkedIn: https://www.linkedin.com/in/neciudan 💼 Show LinkedIn: https://www.linkedin.com/company/senors-scale/ 📸 Instagram: https://www.instagram.com/senorsatscale/ 📸 Dan's Instagram: https://www.instagram.com/neciudev ADDITIONAL RESOURCES: - TanStack Router: https://tanstack.com/router - Engineering Management for the Rest of Us by Sarah Drasner - Scaling Fast by Swizec Teller - Swizec's newsletter: https://swizec.com #TanStackRouter #React #Monorepo #MicroFrontends #FrontendArchitecture #TypeScript #StaffEngineer #SenorsAtScale 💬 Have you ever had to migrate a router in a live codebase? What pattern did you use? Drop it in the comments.

  • S2 · E18
    May 31 · 48 min

    Redux at Scale with Mark Erikson | State Management, RTK Query, Time Travel Debugging

    What happens when the person maintaining one of the most widely used libraries on the internet tells you AI is coming for debugging, too? Mark Erikson is the maintainer of Redux, creator of Redux Toolkit, and a senior front-end engineer at Replay.io, where he works on a time-traveling debugger. He's been shipping software since 2008, from emulating legacy CPUs in old aircraft at Northrop Grumman to modernizing a Redux codebase used by millions of developers. And remarkably, Redux has always been a free-time project for him. In this episode, Dan sits down with Mark to trace the full arc of Redux: how it started as a 2015 conference demo on time travel, how it conquered (and then over-saturated) the React ecosystem, and how Redux Toolkit and RTK Query reshaped the way people actually use it today. We also get into one of the most fascinating technical stories in the episode, how Mark got source maps into React's build pipeline and what happened next. Then we look forward. Mark walks through how Replay records the entire browser, how Replay MCP gives AI agents the same time travel debugging tools a human would have, and a real example where an agent went from fumbling for 15 minutes to finding a root cause in under two. Key Topics: - The origin of Redux and how it killed off the other Flux libraries - What Redux Toolkit solves and the persistent "boilerplate" myth - RTK Query vs React Query design tradeoffs - The listener middleware and a two-year API design journey - Getting source maps into React's build pipeline - How Replay records and replays the entire browser - Replay MCP and AI agents that auto-investigate failing tests GUEST LINKS 💼 https://www.linkedin.com/in/markerikson 🐦 https://twitter.com/acemarke 🐙 https://github.com/markerikson 🌐 https://blog.isquaredsoftware.com 🦋 https://bsky.app/profile/acemarke.dev FOLLOW & SUBSCRIBE Instagram: https://www.instagram.com/senorsatscale/ Dan's Instagram: https://www.instagram.com/neciudev Podcast: https://neciudan.dev/senors-at-scale Newsletter: https://neciudan.dev/subscribe Dan's LinkedIn: https://www.linkedin.com/in/neciudan Show LinkedIn: https://www.linkedin.com/company/senors-scale/ ADDITIONAL RESOURCES Redux: https://redux.js.org Redux Toolkit: https://redux-toolkit.js.org Replay: https://replay.io Mark's blog post on the listener middleware and source maps work: https://blog.isquaredsoftware.com #Redux #ReactJS #JavaScript #StateManagement #WebDevelopment #FrontEnd #SoftwareEngineering #OpenSource #Debugging #ReduxToolkit 💬 What's the one thing you used to think AI would never be able to do for you as an engineer?

  • S2 · E17
    May 24 · 53 min

    TanStack Query at Scale with Dominik Dorfmeister (TkDodo) | Open Source, Knip, Sentry Design System

    What does it actually feel like to maintain a library used by millions of developers every day? In this episode of Seniors at Scale, Dan sits down with Dominik Dorfmeister, better known as TkDodo, the creator and maintainer of TanStack Query and a software engineer at Sentry. Dominik has spent over a decade building frontend tooling and has become one of the most trusted voices in the React and TypeScript ecosystem. Dominik shares how he got into open source during the pandemic lockdowns, simply by answering questions in Discord, and how that habit grew into maintaining one of React's most widely adopted libraries. He talks candidly about the breaking change that went wrong, why major versions are "the pain of his existence," and what he has learned about shipping changes to a community that only shows up with feedback after release. The conversation also digs into his work at Sentry, where he used Knip to remove 28,000 lines of dead code, and his team's work building a new design system within a 10-year-old, million-line codebase. Key Topics: - Getting into open source by answering community questions - Becoming the maintainer of TanStack Query - Tracked queries and the first big performance feature - Why major version releases are so painful - The version 4 to 5 breaking change that went wrong - Epoch versioning as an alternative to semver - Using Knip to find and remove dead code - Building a design system in a large, legacy codebase - What is planned for TanStack Query version 6 Guest: Dominik Dorfmeister (TkDodo) 🌐 Blog: https://tkdodo.eu/blog 🦋 BluSky: https://bsky.app/profile/tkdodo.eu 🐙 GitHub: https://github.com/TkDodo FOLLOW & SUBSCRIBE 💼 LinkedIn: https://www.linkedin.com/company/senors-scale/ 🌐 Podcast: https://neciudan.dev/senors-at-scale 📨 Newsletter: https://neciudan.dev/subscribe 📸 Instagram: https://www.instagram.com/senorsatscale/ Connect with Dan: 💼 LinkedIn: https://www.linkedin.com/in/neciudan 📸 Instagram: https://www.instagram.com/neciudev ADDITIONAL RESOURCES TanStack Query: https://tanstack.com/query Knip: https://knip.dev Sentry: https://sentry.io TkDodo's blog: https://tkdodo.eu/blog #ReactJS #TanStackQuery #OpenSource #FrontendDevelopment #SoftwareEngineering #WebDevelopment #TypeScript #Sentry 💬 What is your take: should libraries do fewer, bigger major versions, or more frequent, smaller ones? Let us know in the comments.

  • S2 · E16
    May 17 · 50 min

    Performance Engineering at Canva with Den Odell (Staff Engineer & Manning Author)

    What happens to "edge cases" when your product serves 250 million people every month? In this episode of Señors at Scale, I'm joined by Den Odell, Staff Software Engineer at Canva and author of "Performance Engineering in Practice" (Manning, 2026). Den works on Canva's Pro Design group, building inside one of the largest React/TypeScript codebases on the planet, serving 250M+ monthly users across 190+ countries. Before Canva, Den spent 9 years at Volvo Cars architecting their Offer Selector and Car Configurator (powering vehicle purchases across 70+ markets), and 13 years at AKQA leading global frontend engineering for Nike, MINI, and Nokia. He's authored three books, the latest of which introduces the Fast by Default framework, a methodology for treating performance as a design decision from day one rather than a panic fix at the end. We get into how Canva ships safely at a planetary scale (feature flags, dogfooding, geofenced rollouts, test parties), the protobuf-based RPC layer powering their frontend/backend communication, async-first culture across global timezones, and why most teams are stuck in what Den calls the Performance Decay Cycle. Key Topics: Why bugs scale with your user base (and what to do about it) Canva's release pipeline: staff → beta → geofenced regions → world Test parties, dogfooding, and catching weirdness before users do Protogen, CDF, and how Canva moves data between frontend and backend Operational transforms for real-time collaboration The Performance Decay Cycle and why "performance sprints" are broken Fast by Default: making speed everyone's responsibility, not just engineering Perceived performance, AI loading states, and the Pac-Man tape loader lesson Async work culture when "the sun never sets on the Canva Empire" Building for crazy big goals (what does Canva look like at 1 billion users?) GUEST SOCIALS💼 LinkedIn: https://www.linkedin.com/in/denodell🐦 X/Twitter: https://x.com/denodell🐙 GitHub: https://github.com/denodell🌐 Website: https://denodell.com FOLLOW & SUBSCRIBE🌐 Podcast: https://neciudan.dev/senors-at-scale📧 Newsletter: https://neciudan.dev/subscribe💼 Show LinkedIn: https://www.linkedin.com/company/senors-scale/📸 Instagram: https://www.instagram.com/senorsatscale/💼 Dan's LinkedIn: https://www.linkedin.com/in/neciudan📸 Dan's Instagram: https://www.instagram.com/neciudev ADDITIONAL RESOURCES📘 Performance Engineering in Practice (Manning, 2026): https://www.manning.com/books/performance-engineering-in-practice🔧 Code listings on GitHub: https://github.com/denodell/performance-engineering-in-practice✍️ Den's blog: https://denodell.com/blog📕 The Product-Minded Engineer (Drew Hoskins, O'Reilly): mentioned in episode #Frontend #Canva #FeatureFlags #Dogfooding #PerformanceEngineering #SoftwareEngineering #WebDevelopment #StaffEngineer #ReactJS #TypeScript #Podcast #SenorsAtScale 💬 What's the worst "edge case turned major incident" you've shipped to production? Drop it in the comments.

  • S2 · E15
    May 10 · 54 min

    Frontend at Meta with Evyatar Alush | Hack, Flow, Sapling, Open Source at Scale

    What does engineering at Meta actually look like from the inside? Spoiler: almost nothing you know from outside applies. In this episode, Dan sits down with Evyatar Alush, Software Engineer at Meta in Tel Aviv and the creator of EmojiPicker React (600K+ weekly downloads) and Vest. Evyatar's journey is one of the most unusual on the show: no degree, no high school diploma, learned JavaScript on Code Academy during military night shifts in a server room, then talked his way into Fiverr, scaled to Front End Platform Lead, and got recruited into Facebook in 2019. We get into what it's actually like inside Meta's frontend infrastructure: Hack instead of PHP, Flow instead of TypeScript, Relay instead of Apollo, Sapling instead of Git, stacked diffs instead of pull requests, and a custom everything (testing frameworks, ORMs, dev servers, data centers). We also cover his open source philosophy, why he builds his own libraries instead of pulling dependencies, the supply chain risks of modern npm, and how AI-assisted code is reshaping open source maintainer work. Key Topics: - Learning to code on military night shifts with zero CS background - Joining Fiverr with one year of experience and bluffing through the interview - Building Fiverr's notification system, in-app inbox, and toast library - Creating EmojiPicker React from a Fiverr internal tool - The "Unmask" manifesto and starting Fiverr's frontend infrastructure team - Designing the Front Ants team by faking the trappings of a real team - Building micro-frontends that bridge a Ruby on Rails monolith and React - Saying no to Facebook on the first email - Interviewing at Meta in London (and the Dan Abramov interview) - The Calibra/Diem crypto wallet team during COVID - Hack vs PHP, Flow vs TypeScript, Relay vs Apollo, Sapling vs Git - Stacked diffs and why ex-Meta engineers miss them - Why "move fast and break things" is dead at Meta - Code review, dev mod servers, and end-to-end testing at scale - Open source maintenance in the AI era and Cursor-generated PRs - Why he owns the "context" package on npm GUEST: Evyatar Alush 💼 LinkedIn: https://www.linkedin.com/in/evyataralush-5b760866 🐙 GitHub: https://github.com/ealush 🌐 EmojiPicker React: https://github.com/ealush/emoji-picker-react 🌐 Vest: https://vestjs.dev FOLLOW & SUBSCRIBE 📸 Instagram: https://www.instagram.com/senorsatscale/ 📸 Instagram: https://www.instagram.com/neciudev 🎙 Podcast: https://neciudan.dev/senors-at-scale 📬 Newsletter: https://neciudan.dev/subscribe 💼 LinkedIn: https://www.linkedin.com/in/neciudan 💼 LinkedIn: https://www.linkedin.com/company/senors-scale/ ADDITIONAL RESOURCES - EmojiPicker React: https://www.npmjs.com/package/emoji-picker-react - Vest (form validation): https://vestjs.dev - Sapling (Meta's source control): https://sapling-scm.com - The Hack language: https://hacklang.org - Flow: https://flow.org - Relay: https://relay.dev - The Design of Everyday Things by Don Norman - Never Split the Difference by Chris Voss #Meta #Facebook #Frontend #ReactJS #HackLang #Flow #Relay #Sapling #StackedDiffs #OpenSource #EmojiPickerReact #Vest #SoftwareEngineering #SenorsAtScale 💬 What's your take on Meta's "everything in-house" engineering culture? Would you rather work with familiar tools or relearn engineering from scratch for better internal infrastructure?

  • S2 · E14
    May 3 · 51 min

    React Native at Scale with Kadi Kraman, Software Developer at Expo | Mobile Development, EAS, OTA Updates

    What does it actually take to build production React Native apps in 2026, and where does Expo fit in? In this episode of Señors at Scale, Dan sits down with Kadi Kraman, software developer at Expo, who has spent over six years in the React Native ecosystem, wearing every hat from IC to director. Kadi shares the story of how she went from writing C++ in a maths degree to becoming one of the early React Native engineers at Formidable, and eventually joining Expo to work on the platform itself. We dig into what makes React Native genuinely competitive with native iOS and Android development today, why Expo Go is now just for prototyping, how EAS workflows and fingerprint-based repacks dramatically speed up CI, the real story on OTA updates (and where the legal gray area sits), and what's still missing from the ecosystem. Kadi also gives a rare look at the new Expo agent for vibe-coding mobile apps, the case for React Native brownfield, and her honest take on Lynx as competition. Key Topics: - Why React Native + Expo is faster than native Xcode/Android Studio workflows - The mental shift from web to native (display points, gestures, pixel density) - Expo Go vs development builds, and why the recommendation has changed - EAS workflows, repack jobs, and project fingerprints - React Native performance, list rendering, and the React Compiler - OTA updates: when to use them, when not to, and what the stores actually allow - Debugging strategies (expo-doctor, native logs, AI-assisted log analysis) - Brownfield React Native and embedding RN screens into existing native apps - Lynx, competition, and the future of cross-platform mobile - Career advice on imposter syndrome, applying anyway, and finding talk topics GUEST: Kadi Kraman, Software Developer at Expo 💼 LinkedIn: https://www.linkedin.com/in/kadikraman/ 🐦 Twitter/X: https://x.com/kadikraman 🐙 GitHub: https://github.com/kadikraman 🌐 Website: https://kadikraman.com/ FOLLOW & SUBSCRIBE 🎙️ Podcast: https://neciudan.dev/senors-at-scale 📩 Newsletter: https://neciudan.dev/subscribe 💼 LinkedIn (Show): https://www.linkedin.com/company/senors-scale/ 💼 LinkedIn (Dan): https://www.linkedin.com/in/neciudan 📸 Instagram (Show): https://www.instagram.com/senorsatscale/ 📸 Instagram (Dan): https://www.instagram.com/neciudev ADDITIONAL RESOURCES - Expo: https://expo.dev/ - Kadi's "From Web to Native with React" blog post: https://expo.dev/blog - EAS Workflows: https://docs.expo.dev/eas-workflows/get-started/ - Expo Doctor: https://docs.expo.dev/more/expo-cli/#expo-doctor - Expo Fetch (streaming support): https://docs.expo.dev/versions/latest/sdk/expo/ #ReactNative #Expo #MobileDevelopment #JavaScript #iOS #Android #EAS #ExpoRouter #SoftwareEngineering #SeñorsAtScale 💬 What's your biggest pain point building React Native apps today, and have EAS workflows changed your CI setup?

  • S2 · E13
    April 26 · 52 min

    AI at Scale with Nico Martin from Hugging Face | Transformers.js, Tokenizers, On-Device Inference

    Can you really run state-of-the-art machine learning models directly in the browser, with no server, no API calls, and full privacy by default? In this episode, Nico Martin, Open Source Machine Learning Engineer at Hugging Face and Google Developer Expert in AI and Web Technologies, walks through how Transformers.js makes on-device AI a reality. Nico's journey is anything but conventional. He started as a ski and windsurf instructor, taught himself web development on the side, spent years as a freelancer (including five at a bank building e-banking front ends), and recently landed what he calls his dream job at Hugging Face. We unpack what Hugging Face actually is (the GitHub for machine learning), how Transformers.js brings the Python Transformers API to the browser, and the real engineering challenges of running models on whatever hardware your users happen to have. Nico explains quantization, ONNX as the standard for portable model architectures, the role of tokenizers, how text becomes tensors, and why WebGPU matters for running larger models client-side. We also dig into the bigger picture: privacy-preserving AI, the difference between open weights and truly open source models, agents and MCP, and what front-end developers should actually learn to stay relevant in an AI-first world. Key Topics: - What Hugging Face is and the role of the Hub, Transformers, and Diffusers - Transformers.js: bringing Python Transformers API to JavaScript and the browser - The biggest challenge of browser ML: running on unknown client hardware - Quantization explained (Q4, 4-bit vs 16/32-bit) and how it compresses models - ONNX and ONNX Runtime Web: the standard for portable model architectures - Open weights vs open source models and why the distinction matters - Tokenizers, token IDs, and why each model needs its own tokenizer - From text to tensors: pre-processing, inference, and post-processing - Text embeddings explained through a simple animal feature analogy - WebGPU and what it unlocks for in-browser inference - Agents, tool calling, MCP, and how context windows get consumed - Advice for developers who want to break into AI and ML engineering 🔗 FOLLOW NICO 💼 LinkedIn: https://www.linkedin.com/in/nicodotdev/ 🐦 X/Twitter: https://twitter.com/nic_o_martin 🦋 Bluesky: https://bsky.app/profile/nico.dev 🐙 GitHub: https://github.com/nico-martin 🌐 Website: https://nico.dev 🎙️ FOLLOW & SUBSCRIBE 📸 Instagram: https://www.instagram.com/senorsatscale/ 📸 Instagram: https://www.instagram.com/neciudev 🎙 Podcast URL: https://neciudan.dev/senors-at-scale 📬 Newsletter: https://neciudan.dev/subscribe 💼 LinkedIn: https://www.linkedin.com/in/neciudan 💼 LinkedIn: https://www.linkedin.com/company/senors-scale/ 📚 ADDITIONAL RESOURCES - Transformers.js: https://huggingface.co/docs/transformers.js - Hugging Face: https://huggingface.co - ONNX: https://onnx.ai - ONNX Runtime: https://onnxruntime.ai - WebGPU: https://www.w3.org/TR/webgpu/ - Utopia for Realists by Rutger Bregman #MachineLearning #AI #HuggingFace #TransformersJS #WebML #OnDeviceAI #WebGPU #ONNX #JavaScript #Frontend #WebDev #SenorsAtScale #OpenSource 💬 Would you trust on-device AI over cloud-based models for sensitive data? Share your thoughts in the comments!

  • S2 · E12
    April 19 · 46 min

    Scaling Frontend at Perk with Giorgio Polvara | Monolith to Microfrontends, Vite, Zod

    What does it actually take to scale a frontend from 15 people in a converted flat to a 1,800-person unicorn, and then migrate the whole thing to microfrontends without breaking anyone's week? In this episode, Dan sits down with Giorgio Polvara, Staff Engineer at Perk (formerly TravelPerk) and the original creator of @testing-library/user-event (1M+ weekly npm downloads). Giorgio joined TravelPerk as employee #15, set up the frontend foundations that still power the product today, left to try engineering management at Toptal, realized he missed building, and came back as Staff. They get into the microfrontend migration that replaced a monolithic React app with vertically-split single-page apps served at the infrastructure layer, the rebrand that changed the name, domain, logo, and colors simultaneously, and the philosophy that ties it all together: you're not building features, you're improving a system that happens to produce features. Key Topics: - Scaling a frontend team from 7 engineers to a full platform tribe - Why 20% refactoring time is the wrong model - Monolith to microfrontends: SingleSPA vs the vertical-split architecture they built - Managing shared dependencies with pnpm, Syncpack, and Vite plugin packages - Contract testing with Pact vs runtime schema validation with Zod - Rebranding an entire product behind a feature flag, without leaking the design - Why Giorgio tried engineering management and went back to IC - Staff engineer advice: propose five solutions, expect one to land 🔗 FOLLOW GIORGIO 💼 LinkedIn: https://www.linkedin.com/in/polvara 🐙 GitHub: https://github.com/Gpx 🌐 npm: https://www.npmjs.com/package/@testing-library/user-event 🎙️ FOLLOW & SUBSCRIBE 📸 Instagram: https://www.instagram.com/senorsatscale/ 📸 Instagram: https://www.instagram.com/neciudev 🎙 Podcast URL: https://neciudan.dev/senors-at-scale 📬 Newsletter: https://neciudan.dev/subscribe 💼 LinkedIn: https://www.linkedin.com/in/neciudan 💼 LinkedIn: https://www.linkedin.com/company/senors-scale/ 📚 ADDITIONAL RESOURCES - A Philosophy of Software Design by John Ousterhout - Out of the Tar Pit (Moseley & Marks) - No Silver Bullet (Fred Brooks) - @testing-library/user-event: https://www.npmjs.com/package/@testing-library/user-event - SingleSPA: https://single-spa.js.org - Vite: https://vitejs.dev - Pact (contract testing): https://pact.io - Zod: https://zod.dev #staffengineer #microfrontends #frontendarchitecture #perk #travelperk #reactjs #softwarearchitecture #engineeringleadership #devtools #softwaredesign #senorsatscale 💬 How does your team handle the tension between shipping features and keeping the system healthy? Drop a comment 👇

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