I build developer tools, and I teach people how to use them.
Creator of Fallow, the Rust-powered codebase analyzer for TypeScript and JavaScript, built on Oxc. Builder of IsAgentReady. Twelve years of shipping for the web before that.
Building Fallow · open to DevRel & developer-tools roles
For twelve years I built the web for other people: design systems, government portals, and apps hundreds of thousands of people use every day. Along the way I kept reaching for tools that did not exist yet. So now I build them, in the open, and I explain them from a stage, in docs, and in the terminal.
Rust, TypeScript, Elixir. From an Oxc-based analyzer to Phoenix LiveView apps and MCP servers. I ship the thing I talk about.
Talks at dotJS, React Advanced and React Amsterdam, plus docs and agent skills. I try to make hard tooling ideas feel obvious.
Performance, SEO and AEO. IsAgentReady exists because I wanted to measure how products get found by people and by agents.
Codebase intelligence for TypeScript and JavaScript.
Every import is an edge. Fallow resolves all of them across 100+ framework plugins, so it knows which files, exports and dependencies nothing reaches.
What you are looking at
The graph behind this panel is live WebGL, drawn in the same colours.
Built in Rust on Oxc, with no TypeScript compiler and no Node.js runtime. Deterministic output with typed JSON contracts, so CI and coding agents can act on it without guessing.
What one run reports
CLI, VS Code, Neovim, Zed, an LSP server, GitHub Actions, GitLab CI, Node bindings, and an MCP server so coding agents check the blast radius before they edit.
npx fallow audit Audit scope: 19 changed files vs HEAD~15 ● Unused files (2) packages/vitest/src/public/reporters.ts test/coverage-test/test/configuration-options.test-d.ts ● Circular dependencies (6) packages/vitest/src/integrations/vi.ts → wait.ts → vi.ts ✗ dead code: 156 issues · complexity: 6 findings · duplication: 8 clone groups (1.05s)
5.9M
npm downloads last month
5.3k
GitHub stars
100+
framework plugins
74 ms
to analyze preact
Is your website ready for AI agents?
Search is splitting in two: people and agents. IsAgentReady scans any site against 41 checkpoints and tells you exactly what to fix so LLMs and agents can find, understand and act on it. Think of it as Lighthouse for answer engines.
Ready to scan
Example scan. The real one runs at isagentready.com
Web app
Letter grades, public rankings, and PDF reports.
CLI
Scan from the terminal or in CI.
MCP server
Agents can scan sites and read the rankings.
Agent skills
Fix the findings inside your editor.
Tools for developers, and more and more for their agents: Rust SDKs on the Oxc stack, MCP servers that turn real APIs into safe tools, and skills that teach agents to use them. All public, all MIT licensed.
Merged pull requests to projects I use every day, from Preact support in Storybook to a coverage hook in Vitest.
LatestdotJS · Paris · Sep 2026
Linters check files and TypeScript checks types, but nothing checks the codebase as a whole. Now that agents write more of our code, the questions that matter are codebase-wide: what is dead, what is duplicated, what crosses a boundary. A look at that blind spot, and at how a project-graph view closes it.
Watch on YouTube ↗ (opens in a new tab): JavaScript tooling has a blind spotUpcomingReact Advanced · London · Oct 2026
Generating a React component takes seconds. Changing a real React or Next.js codebase safely does not. How codebase intelligence gives agents the system context to know what is dead, what is duplicated and which boundaries a refactor crosses.
Event page ↗ (opens in a new tab): Agentic Engineering for React Teams: Give Your Coding Agent a MapUpcomingFrontmania · Netherlands · Oct 2026
What it takes to keep a TypeScript or JavaScript codebase healthy when more of it is written by agents, with Fallow as the working example.
Event page ↗ (opens in a new tab): Codebase intelligence with FallowAI Coding Summit · London · Jul 2026
AI tools write good local diffs but miss repo-wide truth: dead exports, duplicated logic, boundary violations and creeping complexity. A workflow where the agent generates, deterministic analysis checks, findings flow back through CLI and MCP, and CI gates the drift.
Watch on GitNation ↗ (opens in a new tab): Fast Code Generation Is Easy. Safe System-level Change Is Not.FrontValue Meetup · Netherlands · Jun 2026
Vibe coding works until the codebase gets big. Why agent-written code needs deterministic checks, and what those checks look like in a real team.
Event page ↗ (opens in a new tab): Vibe Coding Doesn't Scale: Deterministic Tooling for Agentic EngineeringReact Amsterdam Meetup · Amsterdam · Feb 2019
The story of the ANWB design system: moving many front-end applications onto one shared component architecture, the process behind it, and the technical choices along the way.
Watch on YouTube ↗ (opens in a new tab): Building a Design System with (P)ReactReact Amsterdam Meetup · Amsterdam · 2017
Static analysis, type checking and tests: how to layer them in a React codebase so you can ship often with real confidence instead of false security.
Watch on YouTube ↗ (opens in a new tab): React and the Three Layers of TestingRotterdam The Hague Front-end Meetup · The Hague · 2018
Component architecture for 200 front-end applications and 30 developers: patterns for flexible, composable components that scale across teams.
Slides (PDF) ↗ (opens in a new tab): Creating a (P)React Component LibraryFrom front-end consultant to tech lead to chapter lead for 35 developers, across ANWB, the Dutch government and agencies. Design systems, accessibility, and architecture for sites with hundreds of thousands of daily users.
2025 — 2026
Senior Full-stack Developer
Built Port of Rotterdam Innovation Bridge solo, and new sites for Acorn, Zeeuws Museum and Rotterdam Inclusief. Worked on Oorlogsbronnen, the RotterdamPas and VPRO ClubLees apps, and the new Rijkshuisstijl in NL Design System.
2024 —
Senior Front-end Developer via ICTU, for the IND and RvIG
Front ends Dutch residents rely on. A Vue 3 JSON Forms adapter library used in about 10 register front ends at the Immigration and Naturalisation Service. Passport and travel-document application flows for RvIG, with Keycloak, NL Design System and audited WCAG AA accessibility.
2022 — 2024
Senior Front-end Developer
Led the rebuild of sdu.nl from scratch on Next.js and Contentful. Worked on a design system shared by many products, and CI/CD on GitHub Actions and AWS.
2020 — 2024
Tech Lead, Quarantine & Vaccination
The Dutch COVID platforms. A setup that took new Rijkshuisstijl sites live within weeks of starting, with OWASP, WCAG 2.1 audits and Kubernetes on OpenShift.
2019 — 2020
Chapter Lead Front-end
Set the front-end vision for 35 developers. Designed a micro-frontend architecture over Bloomreach, Sitecore and Magento, and a high-traffic e-commerce platform.
2016 — 2019
Tech Lead, Design System & Traffic
Built the ANWB design system in Preact. Solution architect for the traffic and route planner apps, which serve about 300,000 visitors a day.
2013 — 2016
Front-end Consultant
Front-end specialist for ANWB. Designed and taught the 7-day front-end course for young professionals and the Advanced Front-End program.
via Norday · 2025 — 2026
Innovation Bridge: an interactive map of the port’s innovation ecosystem with a strategy canvas, built solo on Next.js 16, Mapbox and a Statamic back end.
via Norday · 2026
A new website for Acorn, which helps smallholder farmers turn agroforestry into carbon income.
via Norday · 2025 — 2026
The national WWII sources platform, linking millions of records into life stories for more than 750,000 people.
via Norday · 2025
The Rotterdam Inclusief website for the municipality, on Next.js with the Rotterdam Design System.
via Norday · 2025 — 2026
The new Rijkshuisstijl as open-source NL Design System components and design tokens, for central-government websites and apps.
via Norday · 2025
The museum’s website: a Next.js front end on Statamic, with Algolia-powered search through the collection.
via Norday · 2025 — 2026
ClubLees, a reading app for children, in React Native with an immersive reader module.
via Norday · 2025 — 2026
The RotterdamPas app for iOS and Android, built in React Native.
via ICTU · 2025 —
A Vue 3 JSON Forms adapter library and form runtime used across about ten register front ends of the Immigration and Naturalisation Service.
via ICTU · 2024 —
Accessible passport and travel-document application flows, with Keycloak and the NL Design System, audited to WCAG AA.
DevRel, developer tools, growth engineering, or a hard tooling problem you want explained well. I would love to hear about it.
