# Roy van Kaathoven

> Independent software engineer and architect. Backend, frontend, and infrastructure — shipping production systems end to end.

Personal site of Roy van Kaathoven, an independent software engineer and architect available for freelance and contract work. Remote, working in Dutch and English. Content below is grouped by services offered, client case studies, open-source projects, and writing.

## Key pages

- [Roy van Kaathoven — software engineer & architect](https://royvankaathoven.nl/): Independent software engineer and architect. Backend, frontend, and infrastructure — shipping production systems end to end.
- [About](https://royvankaathoven.nl/about): Background, how I work, and what I have shipped.
- [Services](https://royvankaathoven.nl/services): Productised consulting engagements.
- [Work](https://royvankaathoven.nl/work): Client case studies with outcomes.
- [Open source](https://royvankaathoven.nl/open-source): Libraries and tools I maintain.
- [Blog](https://royvankaathoven.nl/blog): Writing on architecture and engineering practice.
- [Radar](https://royvankaathoven.nl/radar): Tools and technologies I use, and my stance on each.

## Services

- [Interim & Fractional CTO](https://royvankaathoven.nl/services/interim-cto): Hands-on technical leadership from someone who has founded, built, and scaled engineering from the first commit — for founders without a technical co-founder and teams that have outgrown their original setup.
- [MVP in a week](https://royvankaathoven.nl/services/mvp-in-a-week): A focused, AI-first sprint that turns one sharp idea into a deployed product you can put in front of users, on infrastructure you own and can build the next version on.
- [Infrastructure management](https://royvankaathoven.nl/services/infrastructure): Someone to own the boring-critical layer (the cloud, the pipelines, the reliability and the bill) so your engineers ship features instead of fighting the platform.
- [AI automation](https://royvankaathoven.nl/services/ai-automation): Practical AI built into the way your company already works — agents and automations wired into your real systems, so the busywork happens on its own and your team gets one assistant instead of five disconnected tools.
- [Web & app development](https://royvankaathoven.nl/services/app-development): End-to-end product engineering for web and mobile — one person who owns the whole stack, from the data model and APIs through to an interface that's fast, accessible, and pleasant to use.
- [Architecture & code review](https://royvankaathoven.nl/services/architecture-review): A focused, honest assessment of your architecture and codebase — the bottlenecks, the real risks, and a prioritised plan — from someone who has owned production systems through scale and acquisition.
- [AI marketing services](https://royvankaathoven.nl/services/ai-marketing): Marketing built the same way I build products — AI-first and wired into your own channels, so content gets planned, produced, and published across every network without a growing headcount.

## Case studies

- [Live-streaming platform](https://royvankaathoven.nl/work/live-streaming-platform): An interactive consumer live-streaming platform where creators broadcast live to a real-time audience that can chat, react, and send virtual gifts. I co-founded it, wrote the first line of code, and led it as CTO for six years — through global scale, a company of around fifty, and an acquisition.
- [Wellness platform for creators](https://royvankaathoven.nl/work/wellness-platform): A holistic lifestyle and consciousness platform — a creator-driven ecosystem where practitioners across yoga, meditation, breathwork, nutrition, and spiritual education monetise their expertise. I'm the founding engineer, and a small, AI-first team is shipping in months what would normally take several teams many more.
- [Online gaming platform](https://royvankaathoven.nl/work/nightpixel): Nightpixel is a consumer gaming platform — think Nutaku, but non-adult — where players browse a catalog of online games and play them in-browser against a single token wallet. I led the engineering and the launch: I built the SDK and server-to-server integration that lets third-party game servers talk to the platform, wired up the payment providers behind the token economy, shipped a native mobile app that doubled as an app store, and coordinated the integration work with game teams in China.
- [Sakurai](https://royvankaathoven.nl/work/sakurai): Sakurai is an internal AI agent platform I designed and built — a single, Slack-native assistant that automates a company's day-to-day work, from customer support and engineering to analytics and ops, by turning internal services into tools its agents can actually use.
- [Advanced-Forms](https://royvankaathoven.nl/work/advanced-forms): Advanced-Forms is enterprise Document Output Management — think n8n, but for documents. Business users visually design how their ERP data turns into documents — layout, business rules, distribution and archiving — on top of large Microsoft Dynamics, AX and SAP deployments, without waiting on IT or a vendor. I rebuilt its conversion core, turned its config files into a drag-and-drop designer, and led the product.
- [Autarco Helios](https://royvankaathoven.nl/work/autarco-helios): Helios is a web-based solar design tool for Autarco. Dealers and customers draw their roof on a satellite map and instantly see how many panels fit and how much energy the system would generate.
- [Seedit](https://royvankaathoven.nl/work/seedit): A multi-chain crypto tipping bot for Telegram. Every community member gets a custodial wallet, and tipping, airdrops, and peer-to-peer trading happen with a single chat command — across TRON, Ontology, Binance DEX, and Solana, with over a million wallets created.
- [Companion AI](https://royvankaathoven.nl/work/companion-ai): A white-label AI social platform where AI companions post, chat, and form relationships with users. One backend on Cloudflare's edge powers several independently branded consumer sites — built solo as a Turborepo monorepo on React 19, Hono, and Cloudflare Workers.
- [Social publishing platform](https://royvankaathoven.nl/work/socialog): Socialog is a social-media scheduling and publishing SaaS I built and run solo. You write a post once, pick your accounts and a time, and a Cloudflare-edge publish engine fans it out to X, Instagram, Threads, LinkedIn, YouTube, Pinterest and Paragraph — each with its own adapter for that platform's quirks. The whole product is also exposed to AI agents over MCP and a REST API, so a post can be scheduled by a human in the calendar or by an agent through a tool call.
- [Bikkel](https://royvankaathoven.nl/work/bikkel): A workout tracker built around reusable routines, a set-by-set logger, and progress you can actually see over months. Bikkel is two surfaces over one shared core — a phone-first training app and a desktop planning hub — shipped as a single Cloudflare Worker on TanStack Start and Drizzle. It also ships a built-in MCP server, so your training data has a first-class API an AI assistant can connect to and reason over. I built the whole thing solo.
- [MandarinAI](https://royvankaathoven.nl/work/mandarin-ai): MandarinAI is a Chinese-learning platform I designed and built on my own. Its core is a closed loop between spaced repetition and reading: an FSRS scheduler decides which words you're about to forget, and an LLM writes graded stories from exactly those words, so every review earns its keep. It runs edge-native — one Cloudflare Worker serving both the app and the API — on TanStack Start, Hono, Drizzle and Postgres.

## Open source

- [clu](https://royvankaathoven.nl/open-source/clu): A local-first issue tracker that lives in a single SQLite file, built for the new problem of coordinating several AI coding agents on one machine. Agents atomically claim work so two never grab the same task, follow a dependency graph to know what's unblocked, and leave a full audit trail — with no daemon, no server, and no network.
- [yori](https://royvankaathoven.nl/open-source/yori): The home for everything you tell your AI. yori is a local, file-based library of reusable prompts, agents, slash-commands, and skills that you can list, edit, compose, and render into ready-to-pipe text. It's a pure renderer — text in, text out — so you own the model call.
- [dumont](https://royvankaathoven.nl/open-source/dumont): One filesystem over everything. dumont puts local disk, S3-compatible object stores, Bunny, archives, and HTTP behind a single consistent interface, so the same handful of verbs work no matter where the bytes live — and data flows between unlike stores with one command.
- [beam](https://royvankaathoven.nl/open-source/beam): A webhook tunnel you actually own. beam gives you a stable public URL on your own Cloudflare edge and pushes every delivery down a WebSocket to a local CLI, which replays it to whatever port you point at. Same job as ngrok or Smee.io — except there's no tunnel vendor in the middle, just one Worker, one Durable Object, and one Go binary.
- [InlineAttachment](https://royvankaathoven.nl/open-source/inlineattachment): A small, dependency-free JavaScript library that adds upload to a plain textarea or CodeMirror instance — drag-drop a file in, or paste an image straight from the clipboard, and it uploads in the background and drops the link in at the cursor. Just like pasting an image into GitHub.
- [Contropad](https://royvankaathoven.nl/open-source/contropad): Use the phone already in your pocket as a game controller. Contropad pairs a web-based controller that runs in the phone's browser with a small Windows server that turns those touches into real joystick input via vJoy — so any game that reads a gamepad sees the phone as the real thing. No app store, no extra hardware.

## Writing

- [SakurAI: giving the company one name for all its AI](https://royvankaathoven.nl/blog/sakurai-one-name-for-all-ai): An internal Slack bot that turned a pile of disconnected AI models and internal tools into one thing you can just talk to — and what happens when a sentence becomes the interface to the whole company. (published 2026-06-28)
- [Why I migrated to TanStack Start](https://royvankaathoven.nl/blog/migration-to-tanstack): Moving a React app off Next.js and onto TanStack Start, Vite, and Cloudflare Workers — what got simpler, what got more explicit, and how to drive a big migration with codemods instead of a rewrite. (published 2026-06-25)
- [Designing the factory: AI coding beyond the prompt](https://royvankaathoven.nl/blog/designing-the-factory): What changes when you manage a fleet of coding agents instead of one — the middle loop, the eight stages of adoption, and why judgment got more valuable, not less. (published 2026-06-24)

## Availability by role and region

- [AI Automation & AI Engineering — Roy van Kaathoven](https://royvankaathoven.nl/ai-automation): I build production-grade AI automation and LLM features — and ship them fast with small, AI-augmented teams, with fifteen years of engineering behind every system. Language: en.
- [Fractional & Remote CTO for Taiwan & Asia — Roy van Kaathoven](https://royvankaathoven.nl/fractional-cto-taiwan): Fractional and remote CTO who founded and scaled an engineering org from Taiwan to an acquisition. Hands-on technical leadership across APAC and Europe. Language: en.
- [Freelance Software Architect — Roy van Kaathoven](https://royvankaathoven.nl/freelance-software-architect): Freelance software architect who designs systems simple enough to trust and scale. Remote, on Taipei time with European-hours availability, working in Dutch and English. Language: en.
- [Freelance Software Engineer in the Netherlands — Roy van Kaathoven](https://royvankaathoven.nl/freelance-software-engineer-netherlands): Independent full-stack software engineer for Dutch teams. Remote and based in Taipei, working in Dutch and English during European hours, with 12+ years building and shipping production systems end to end. Language: en.
- [Freelance Software Engineer in Taipei — Roy van Kaathoven](https://royvankaathoven.nl/freelance-software-engineer-taipei): Independent full-stack software engineer who built and led a 50-person engineering org from Taiwan. Remote, English-speaking, with APAC and Europe timezone coverage. Language: en.
- [Interim & Fractional CTO — Roy van Kaathoven](https://royvankaathoven.nl/interim-cto): Interim and fractional CTO who has founded, built, and scaled engineering from the first commit. Remote, Dutch and English, available for hands-on technical leadership. Language: en.
- [AI-automatisering & AI Engineering — Roy van Kaathoven](https://royvankaathoven.nl/nl/ai-automatisering): Ik bouw productiewaardige AI-automatisering en LLM-features — en lever ze snel met kleine, AI-versterkte teams, met vijftien jaar engineering achter elk systeem. Language: nl.
- [Freelance Software Architect — Roy van Kaathoven](https://royvankaathoven.nl/nl/freelance-software-architect): Freelance software architect die systemen ontwerpt die eenvoudig genoeg zijn om op te vertrouwen en te schalen. Remote vanuit Taipei, beschikbaar tijdens Europese uren, in het Nederlands en Engels. Language: nl.
- [Freelance Software Engineer Nederland — Roy van Kaathoven](https://royvankaathoven.nl/nl/freelance-software-engineer-nederland): Zelfstandige full-stack software engineer voor Nederlandse teams. Remote vanuit Taipei, in het Nederlands en Engels tijdens Europese uren, met 12+ jaar ervaring in het bouwen en opleveren van productiesystemen. Language: nl.
- [Interim CTO — Roy van Kaathoven](https://royvankaathoven.nl/nl/interim-cto): Interim en fractional CTO die engineering vanaf de eerste commit heeft opgebouwd en geschaald. Remote, Nederlands en Engels, hands-on technisch leiderschap. Language: nl.

## Optional

- [Sitemap](https://royvankaathoven.nl/sitemap.xml): All indexable URLs.
- [RSS feed](https://royvankaathoven.nl/rss.xml): Blog posts as RSS.

## Contact

- Email: royvk@pm.me
- GitHub: https://github.com/rovak