TypeScript, Next.js
Thermozona
A local-first Home Assistant integration for underfloor heating. Zoned PWM/PI control and automatic heat/cool switching, without cloud dependency. Built with TypeScript and Next.js.
Freelance full-stack TypeScript engineer
Freelance TypeScript engineer in Utrecht and Amsterdam
I'm Jaap van der Meer, a freelance full-stack TypeScript engineer based in Utrecht. I help product teams in Amsterdam, Utrecht, Rotterdam and The Hague ship reliable features from idea to production.
LocationUtrecht, Amsterdam, Rotterdam, The Hague
FocusFull-stack product engineering, startup execution, growth
Core stackTypeScript, Next.js, Node.js, React, React Native
About Jaap van der Meer
I've been building web applications for two decades+ as both a founder and a freelance full-stack engineer, from early-stage startups to SaaS products used by thousands.
I work full-stack across backend and frontend. With TypeScript, Next.js and Node.js, I build scalable web applications. Developer or engineer, I bring end-to-end ownership to every project. I'm a fan of TDD and pragmatic engineering, with a sharp eye for UX and performance.
These days I help product teams design APIs, improve architecture, and ship user-facing features quickly and safely.
I work remotely from Utrecht and I'm available for on-site collaboration in Amsterdam, Rotterdam and The Hague. Let's talk about your project over coffee.
Services
Next.js & React Development
Fast, SEO-friendly web apps with the App Router, Server Components, and modern React patterns.
React Native App Development
Cross-platform iOS and Android apps with shared code and logic for maximum efficiency.
MVP Construction
Rapid prototyping and execution for startups. From idea to production-ready MVP in weeks.
AI & LLM Integration
Efficient engineering with an AI-first mindset: systematize workflows, automate the boring parts, and ship faster without sacrificing quality.
Performance & SEO Audits
Deep dives to improve Core Web Vitals, SEO, and overall code quality.
Growth Engineering
Experiment-driven growth: fast iterations, solid analytics, funnels, and performance work that moves the numbers.
Selected products and platforms
Ruby on Rails, React
Rompslomp
My life's work: a simple accounting product for Dutch freelancers. Founded in 2011, grew to a team of 12, and sold to Visma in 2022. Built with Ruby on Rails and React.
Ruby on Rails, React
REFQ
A web app for REFQ B.V. that automated reference checks via questionnaires and generated polished CVs. Built with Ruby on Rails in collaboration with The Playful Company.
Meteor.js
The Lean Scientist
An online learning platform for Climate-KIC that teaches lean methodology. Interactive steps, assignments, and peer reviews. Built with Meteor.js.
Ruby on Rails
Eduapp
A discovery platform connecting education with apps and creative ideas. Built with Ruby on Rails to help educators find and share classroom tools.
Ruby on Rails, Ember.js
Raillogix Planboard
A real-time transport management dashboard tracking train movements across Europe. Built full-stack with Ruby on Rails and Ember.js.
Web product development
Intelleqtive
An innovation platform built with Club van Delft, enabling micro-knowledge transactions between industry and academia.
Analytics product
Worldlogger.com
Started as a 3D globe visualization of web traffic and grew into a full analytics product with real-time geographic insights. Later acquired.
Social video platform
Tweetz.tv
A social video platform that turned Twitter timelines into a continuous stream of shared YouTube videos. Co-created with Ernest Mistiaen. Later acquired.
Realtime collaboration
Tjoon
A real-time music collaboration platform built with colleagues at Suite75. Musicians worldwide could jam together online - an experiment in browser-based audio.