Simon Willison is a British software engineer, open source creator, and AI commentator best known for co-creating the Django web framework and building Datasette, the open-source data exploration tool. He coined the term 'prompt injection' in 2022 and popularized 'AI slop' in 2024 - a word later named Merriam-Webster's 2025 Word of the Year. Through his prolific blog (active since 2002), newsletter with 54,000+ subscribers, and 100+ open source tools, he is one of the most influential independent voices at the intersection of LLMs and open source software.
Swyx (Shawn Wang) and Alessio Fanelli are the co-hosts of Latent Space, the #1 AI Engineering podcast and newsletter with 200,000+ subscribers and 10M+ total readers. Swyx — a former Singapore hedge fund trader turned developer advocate who coined the term 'AI Engineer' — and Alessio — a Forbes 30 Under 30 VC partner and Rome-born dropout-turned-engineer — together define the curriculum and culture of a generation of engineers building with AI.
Addy Osmani is an Irish software engineer and engineering leader who spent nearly 14 years shaping the modern web at Google Chrome - leading the teams behind Lighthouse, Core Web Vitals, Chrome DevTools, Puppeteer, and PageSpeed Insights. Now Director at Google Cloud AI, he bridges Gemini, Vertex AI, and the Agent Development Kit for millions of developers worldwide. Author of multiple O'Reilly books and curator of the Elevate newsletter, Osmani's work has touched over 20 million developers and his open-source projects have become industry standards.
Daniel Stenberg is a Swedish software engineer and the creator of curl and libcurl, tools found on an estimated 20-40 billion devices worldwide - from smartphones and smart TVs to spacecraft and every Windows and macOS installation. A self-taught programmer who began on a Commodore 64 at age 14, he has spent over 25 years maintaining one of the internet's most foundational software projects. He currently works at wolfSSL providing commercial curl support, sits as President of the European Open Source Academy, and contributes actively to internet standards through the IETF. His weekly newsletter chronicles his ongoing work simplifying, securing, and extending curl.
Guillermo Rauch is the founder and CEO of Vercel, the frontend cloud platform that powers millions of developers and some of the world's most visited websites. A self-taught engineer from Lanús, Argentina who never finished high school, Rauch built two of JavaScript's most widely used open-source libraries (Socket.IO and Mongoose), co-created Next.js — the world's most popular React framework — and turned Vercel into a $9.3 billion company with $340 million ARR. He is also one of the most prolific angel investors in tech, with over 700 known investments, and recently launched v0, an AI-powered coding tool with over 3.5 million users.
Lee Robinson is a developer educator and engineering leader who spent five years at Vercel scaling Next.js to over a million monthly active developers, rising from individual contributor to VP of Developer Experience. He now serves as Head of AI Education at Cursor, teaching developers how to build software with AI-powered tools. Known for creating free courses like Mastering Next.js and React 2025, his newsletter 'Optimism (for the web)' and 234K+ Twitter following reflect his belief that great technology should be easy to understand and interesting to learn.
Woz (WOZCODE) is a Claude Code plugin built by MIT engineers Ben Collins and Brad Eckert that cuts AI coding costs by 25-55% and speeds up most tasks by 30-40%. Instead of letting Claude Code burn tokens on bloated built-in file operations, WOZCODE replaces them with smarter, leaner alternatives - three specialized agents (code, explore, plan) that do more with less. It installs in two commands, runs locally with no data exfiltration, and works alongside your existing Claude subscription. Backed by Y Combinator (W25) and a $6M seed round, Woz is building the efficiency layer that makes AI-assisted development economically viable at scale.
x1 is the world's most powerful AI app studio, built for iOS. It replaces chaotic AI demo generators with a structured, end-to-end system that takes builders from raw idea to a production-ready App Store launch - generating native Swift and Xcode code, not throwaway prototypes. With modular studios for product design, branding, onboarding, monetization, and growth, x1 is what happens when someone finally takes AI-assisted app development seriously.
Zatanna is a Y Combinator W26 startup that turns software into agent-first APIs. Most AI agents are stuck navigating clunky UIs to interact with systems that never built a proper API - Zatanna fixes that by observing a workflow once, reverse-engineering the underlying HTTP request sequence, and serving it as a clean, reliable endpoint. No browser scripts, no screen-scraping fragility: just fast, production-grade API access to legacy ERPs, insurance portals, marketplaces, and any operational software your agents need to talk to.
Mark Erikson is the primary maintainer of Redux and creator of Redux Toolkit - the tools that power state management in millions of React applications worldwide. Known online as @acemarke, he became the de facto keeper of Redux in 2016 when Dan Abramov handed off the project. Since then, he has rebuilt Redux's documentation from the ground up, designed the hooks API in React-Redux, and created Redux Toolkit to eliminate the boilerplate that once made Redux notorious. He is a Senior Front-End Engineer at Replay.io and a tireless community fixture - answering questions on Discord, Reddit, Bluesky, and anywhere else developers congregate online.
Mat Ryer is a London-based Go programmer, open-source creator, author, and long-time host of the Go Time podcast. Known for building beloved Go tools like xbar (18k+ GitHub stars), moq, and the `is` testing framework, he has been writing Go since before its v1 release. He authored 'Go Programming Blueprints' and spent years as a principal engineer at Grafana Labs building AI agents and observability tools. His characteristic blend of deep technical craft, game-show energy, and dry British wit has made him one of the Go community's most recognizable voices.
Paul Kinlan is the Lead for Chrome and Web Platform Developer Relations at Google, where he has spent over 16 years championing the open web. From growing up watching his dad repair computers on the Wirral in North West England, to launching Google Web Fundamentals, killing the 300ms click delay, and shepherding tools like Lighthouse, Squoosh, and Workbox into developers' hands, Kinlan has been the web's tireless advocate inside one of its most influential companies. Now he is turning his lens toward AI's impact on the web through his newsletter and blog AI Focus.
Nelson Elhage is a systems engineer turned AI safety researcher who has left fingerprints across the modern software stack. At Anthropic, he co-authored foundational work on mechanistic interpretability and transformer circuits that shaped how the field understands language models. Before that, he was employee ~30 at Stripe and a founding engineer of Sorbet, the Ruby typechecker now used across one of the world's largest payment platforms. His open-source tools - reptyr, livegrep, and ministrace - are staples in the Linux hacker's toolkit. He blogs at 'Made of Bugs' and runs a Buttondown newsletter on computer systems.
Predrag Gruevski is an independent software engineer, open-source creator, and Rust ecosystem luminary best known for building Trustfall - a universal query engine that lets you query anything from APIs to LLMs - and cargo-semver-checks, a semantic versioning linter that's becoming a cornerstone of the Rust publish workflow. A former MIT competitive mathematician turned principal engineer at Kensho Technologies, Predrag brings Olympic-level rigor to API design and compiler technology, writing and speaking extensively on correctness-first software development.
Shawn 'swyx' Wang is a Singapore-born AI engineer, founder, and community builder who pivoted from a $350k/year quantitative finance career to become one of the most influential voices in AI engineering and developer tools. He coined the term 'AI Engineer', co-founded the AI Engineer Summit (now the world's largest technical AI conference for engineers), co-hosts the Latent Space podcast reaching 10M+ readers/listeners, and is the author of the seminal 'Learn in Public' essay that has shaped how millions of developers think about career growth. He is the founder of Smol.ai and a prolific creator with 626+ published essays, talks, and tutorials.
Steve Schoger is a Canadian visual designer and partner at Tailwind Labs, best known for co-authoring Refactoring UI with Adam Wathan - a book and video course that generated over $2.5 million in sales by teaching developers how to design beautiful interfaces. He built a 127K+ Twitter following by sharing meticulous, practical design tips, and created widely-used free resources including Heroicons, Zondicons, and Hero Patterns. His work sits at the intersection of design education and developer tools, making professional UI design accessible to programmers worldwide.
Tanner Linsley is a Salt Lake City-based software engineer, open source creator, and founder of TanStack - the ecosystem behind React Query, TanStack Router, TanStack Table, TanStack Form, and TanStack Start. Co-founder of Nozzle.io, an enterprise SEO platform, Tanner built a multi-million-download open source empire by solving real problems he faced every day, pioneering headless, framework-agnostic, fully type-safe libraries now used by Fortune 500 companies including Apple, Google, Facebook, Amazon, Netflix, Walmart, and Target.
Thorsten Ball is a German software engineer, author, and technical educator best known for his self-published books 'Writing an Interpreter in Go' and 'Writing a Compiler in Go', which have become go-to resources for developers wanting to understand programming language internals. With over two decades of professional software development experience, he currently works at Sourcegraph on Amp, an AI-powered coding agent. He also writes the weekly newsletter 'Register Spill', covering systems programming, developer tools, and the intersection of AI with software engineering.
Vercel is the AI Cloud for frontend developers - a platform that makes deploying web applications as frictionless as a git push. Founded in 2015 as ZEIT by Guillermo Rauch, the Argentine-born dropout who also created Socket.IO and Next.js, Vercel grew from a side-project deployment tool into a $9.3 billion company powering websites for OpenAI, Walmart, Nike, and thousands of startups. Its open-source framework Next.js has logged over 500 million downloads in 12 months alone, and its AI tool v0 lets anyone turn a text prompt into a working web UI. Vercel is the company betting that the next billion developers won't write code at all.
Weights & Biases (W&B) is the AI developer platform that the world's leading machine learning teams use to build, train, and deploy better models faster. Founded in 2017 in San Francisco, W&B provides experiment tracking, model management, and LLMOps tooling used by over 1 million developers - from OpenAI and Meta to Toyota and AstraZeneca. Acquired by CoreWeave in May 2025 for $1.7 billion, W&B is now the software backbone of one of the most important AI infrastructure companies in the world.
ZeroEval is a New York-based AI startup from Y Combinator's Summer 2025 batch building an auto-optimizer for AI agents. Founded by Jonathan Chavez and Sebastian Crossa - two friends who met in college in Mexico - the platform captures every interaction your AI agent makes, scores quality with custom LLM judges, and automatically turns real production data into better prompts. The result: agents that get smarter after launch without manual intervention. Trusted by DoorDash, Datadog, Hugging Face, and Harvard Medical School, ZeroEval closes what the founders call 'the last mile reliability gap' in agentic AI.
Karri Saarinen is the co-founder and CEO of Linear — a $1.25B unicorn project management tool trusted by 66% of Forbes' top 50 AI companies, including OpenAI, Ramp, and Vercel. A Finnish designer-turned-engineer who grew up questioning why everyday objects look ugly, attended 5,000-person LAN parties as a child, and turned that instinct into one of the most respected product careers in Silicon Valley. After shaping the visual language at Coinbase and Airbnb (Cereal typeface, Design Language System, Lottie, Google Material Design Award), he co-founded Linear in 2019 with two fellow Finns from Helsinki — and built it to 20,000+ customers and $100M+ ARR while staying profitable the entire time. His philosophy: quality is the growth strategy, tools embed opinions so choose accordingly, and the best MVP in a crowded category isn't minimal — it's sharply opinionated for a specific audience.
Humanloop was an enterprise LLM development platform founded in 2020 as a UCL spinout, offering prompt management, evaluations, and observability tools for teams building AI applications. With customers like Duolingo and Gusto, it raised ~$8M and reached ~$3.8M ARR before being acqui-hired by Anthropic in August 2025, after which the platform was sunsetted on September 8, 2025. Its technology and team live on inside Anthropic's enterprise console.
Weights & Biases (W&B) is the leading AI developer platform for machine learning and generative AI, offering tools for experiment tracking, hyperparameter optimization, model registry, and LLM application development. Founded in 2017 by Lukas Biewald, Chris Van Pelt, and Shawn Lewis in San Francisco, W&B powers over 1 million developers and 1,400+ organizations — including OpenAI, Meta, and NVIDIA — by making it easier to build, train, evaluate, and deploy AI models. Acquired by CoreWeave for ~$1.7B in May 2025, W&B continues expanding its platform with Weave for LLM/agent observability, cementing its position as the de facto infrastructure for modern AI development.
Predibase was a San Francisco-based AI infrastructure company (founded 2020, acquired by Rubrik in June 2025) that pioneered efficient LLM fine-tuning and serving at scale. Built by the creators of Uber AI's Ludwig and Horovod frameworks, Predibase made it easy for enterprises to fine-tune and deploy open-source LLMs using LoRA adapters — often outperforming GPT-4 on domain-specific tasks for under $8 of compute. Its open-source LoRAX inference server enabled serving thousands of fine-tuned models from a single GPU, dramatically cutting costs. After raising $28M from Greylock and Felicis, Predibase was acquired by cybersecurity firm Rubrik for over $100M to accelerate agentic AI adoption.
Baseten is a San Francisco-based AI inference infrastructure company that provides dedicated and serverless GPU compute for running AI models at scale. Founded in 2019 by four ex-Gumroad engineers, the company has grown into a unicorn with a $5B valuation and $585M in total funding, backed by NVIDIA and other top-tier investors. Baseten powers inference workloads for 100+ enterprises including Cursor, Notion, HeyGen, and Clay, offering an inference stack with near-zero cold starts, proprietary networking, and open-source tooling like Truss for model packaging.
Modal (Modal Labs) is an AI-native serverless cloud computing platform that gives developers instant, elastic access to GPUs and CPUs through a clean Python SDK — no YAML, no Dockerfiles, no infrastructure management required. Founded in 2021 by Spotify ML veteran Erik Bernhardsson, Modal enables AI and ML teams to scale from zero to thousands of GPUs in seconds, paying only for what they use. With customers like Suno, Mistral AI, Harvey, Ramp, and Substack, Modal reached unicorn status at a $1.1B valuation in September 2025 and was reportedly in talks to raise at $2.5B just five months later.
Railway is a Platform-as-a-Service (PaaS) and cloud infrastructure company founded in 2020 by Jake Cooper, positioning itself as 'the developer cloud for the AI era.' It lets developers deploy apps and databases instantly with zero configuration — no DevOps, no FinOps, no SecOps required. Starting from zero marketing spend, Railway grew to over 2.68 million developers and penetrated 31% of Fortune 500 companies purely through word-of-mouth. In January 2026 it raised a $100M Series B to challenge AWS and the legacy cloud giants, underpinned by its own proprietary Railway Metal bare-metal data centers.
PostHog is an all-in-one open-source developer platform for product engineers, combining product analytics, session replay, feature flags, A/B testing, surveys, error tracking, and a data warehouse in a single product. Founded in January 2020 by James Hawkins and Tim Glaser after six pivots, PostHog achieved product-market fit by solving a critical pain point: companies wanted to understand user behavior but couldn't share data with third-party tools due to privacy concerns. Their open-source, self-hostable approach attracted 190,000+ teams, 30,500+ GitHub stars, and $182M in total funding, reaching a $1.4B valuation (unicorn status) in September 2025. PostHog operates as a fully remote, radically transparent, engineering-led company and is now expanding beyond analytics into AI-powered developer automation tools.
Retool is an AI-native low-code platform that enables developers and businesses to rapidly build internal software — dashboards, admin panels, CRUD apps, workflows, and more — by connecting to any database or API. Founded in 2017 by David Hsu and Anthony Guo and backed by Sequoia Capital and Y Combinator, Retool has grown to serve 10,000+ companies and has facilitated the creation of 500,000+ apps, with a $3.2B valuation and ~$120M ARR as of 2025. The company is pushing hard into AI with products like Retool Agents, Workflows, and AppGen, positioning itself as the platform for enterprises replacing off-the-shelf SaaS with custom internal software.