I'm Martijn. A freelance product designer and design engineer, based in the Netherlands. I help teams figure out what to build, design it, and build the parts that matter.
I've been doing this for over 15 years. At startups, at bigger companies like Shopify and Just Eat Takeaway, and at my own studio for nearly six years. Most recently I was Lead Product Designer at AppSignal. Now I'm independent again, and honestly, I'm having a great time.
I only know how good a design is after I've built it. A design can look right and still not work. So I get it close to the real thing as fast as I can: real interactions, real content, real code. AI has made that loop a lot faster, which leaves more room to explore and gets us to better decisions sooner.
Working together
I work best when I get the full loop. Understanding the metrics, talking to customers, grasping the business. Then designing it. Then building it. Some of the things teams bring me in for:
- Shaping a new product or feature, from rough idea to something people can actually use
- Untangling complex flows and interfaces that have grown messy over time
- Prototyping in code, so you can test the real thing before committing to it
- Design systems and tokens that keep design and engineering in sync
- Helping teams bring AI into how they design and build
Have something in mind? Send me a mail and tell me about it.
On the side, I'm building Humic
Alongside client work, I'm building Humic from the ground up. It fixes something that's bugged me for years: design and engineering slowly drifting apart. Humic keeps your design tokens as one source of truth, synced to Figma, available in your codebase, and readable by your AI agents.
It's still in development. Curious? Join the waitlist or read the full story.
Experience
2026 – now · Freelance Product Designer & Design Engineer
Helping teams with product design and design engineering. Design, code, and everything in between.
2025 – 2026 · Lead Product Designer at AppSignal
I led the bigger projects and helped shape the overall design direction. I worked closely with other designers and shifted my workflow towards designing directly in code with AI, rather than going through Figma first.
2023 – 2025 · Senior Product Designer at Picqer
Warehouse management software, from desktop interfaces to mobile apps on Zebra scanners. I shaped features end to end using Shape Up, regularly visited customer warehouses to see how people actually worked, and occasionally dove into the Vue codebase to help build.
2022 – 2023 · Senior Product Designer at Felyx
Solely responsible for all design in the moped sharing app. Everything a rider touched, from finding a scooter to ending the ride. A lot of the work involved safety requirements and municipal regulations across different cities.
2020 – 2021 · Senior Product Designer at Just Eat Takeaway
Worked on T-Connect, the kitchen terminal used in restaurants across multiple countries. Sole designer working with a team of around 12 engineers. Also led the company-wide transition from Sketch to Figma and helped the UK team rebuild their design system.
2015 – 2020 · Owner at Appstronaut
My own studio for nearly six years. Took client ideas from zero to one: strategy, UX, UI, and development. I managed everything from the work itself to client relationships and the commercial side.
2011 – 2014 · Product Designer at Shopify, SeatGeek, Moneybird and freelance.
Find me on LinkedIn or send me a mail.