You work directly with the builder.
No account manager as a go-between. No junior doing the work. Rinnert Deelstra — 20+ years full-stack, e-commerce and AI — advises, designs and builds himself.
Rinnert Deelstra
Senior full-stack developer · Webmakkers
I started building for the web around 2006 — XHTML, CSS, PHP, MySQL, the full early-web toolkit. Early on I wrote my own CMS from scratch to understand the mechanics; a client ran it for four years. That curiosity never left. The PHP5/OOP era brought frameworks — Typo3, CodeIgniter, Slim, Zend, Symfony, Laravel — and gradually the practice grew into what it is today: custom web development, deep e-commerce engineering and, in recent years, AI integration.
What makes the engineering background a little unusual is a formal UX foundation. My bachelor at Hanze University of Applied Sciences Groningen is in Human Technology — user research and interaction design, not just computer science. My graduation project was UX research for hospital medication software; the stakes there sharpen your thinking about clarity and error prevention in ways that carry into every project. That combination — trained interaction designer and experienced engineer — means the quality conversation happens inside one head instead of across a handoff boundary.
On the e-commerce side I have done a large number of Magento builds and v1→v2 migrations, B2B and B2C, including custom checkout flows, Adyen, Mollie and SprayPay payment integrations, and ERP couplings with SAP and Exact. Through agencies Youwe, Custom Media and Aquive Media I worked on brands such as Amac, AGU, Any-Lamp and The Silver Mountain. In 2020 I teamed up with Aquive Media to bring extra senior experience to software agency Icit for the development of Rovanda. These days the stack has moved on: Node.js, Bun, Elysia, Lit, TypeScript and Cloudflare are the core, with realtime sockets (industrial Modbus readouts, live sports streaming) and AI integration rounding it out.
Webmakkers is deliberately kept compact — not to stay small, but to keep quality guaranteed. I work DRY/SOLID/KISS, never trust unvalidated input, and am equally comfortable in a SCRUM team and delivering a project A–Z solo. When capacity or a specialist skill warrants it, I bring in trusted partners for design or extra bandwidth. The toolkit I have built up over the years — 280+ reusable production-ready modules — means more of each project budget goes to your actual requirements rather than reinventing infrastructure. That toolkit is detailed on the home page; here I will just say: it exists because I kept building the same things differently, and eventually decided not to.
Alongside larger clients, I helped 5+ startups go from first idea to live product, across various revenue models — from marketplaces and e-commerce to lead generation. One of the earliest was Coaching Tokens (2010–2013): a platform connecting poker coaches and players, with calculations showing which affiliate poker room would be most lucrative, a coach-booking system and an API that poker room Muchos Poker integrated directly.
AI works. But not for everything, not always, and not without good engineering. I will tell you honestly when something is not ready yet — and only build what delivers value.
Human Technology BSc (Hanze UAS Groningen) · Minor: Entrepreneurial behaviour & conceptual design · Multimedia Design MBO (Friesland College Leeuwarden)
// Stack & specialisationsAnti-hype. Honest. GDPR-by-default.
Three principles that guide every project.
Anti-hype
AI, blockchain, serverless, microservices — every wave of hype attracts clients who want something trending, not something that works. I only build what demonstrably delivers value for your situation. The best compliment is a client who comes back because it worked, not because the pitch was good.
Honest
If a template fits better than custom development, I say so. If AI is not the right choice yet, I say so. If a project is too large for my capacity, I say so. Honesty is cheaper than a mismatch — for you and for me.
GDPR-by-default
Privacy is not a checkbox at the end of the project. It is a design decision you make at the start. Personal data is processed minimally and for specific purposes, EU-hosted, documented. Not because the law requires it — but because it is the only responsible approach.
From conversation to result — step by step.
Every project moves through four phases, in small steps with an honest estimate upfront. If something shifts, you hear it from me immediately — not afterwards.
Intro call
Free and without obligation. I look honestly at where software or AI pays off for your situation — and where it doesn't (yet). 'Not yet' is an answer too.
Design
A graphic design or Figma design we refine together until it's right. I only build after your go — so you know exactly what you're getting beforehand.
Build
Full implementation in weekly milestones. All custom code is yours, documented and transferable. Automated tests, Lighthouse CI and accessibility checks are standard.
Maintain
Monitoring, security updates, further development and adjustments. Cancellable monthly, no annual contracts.
Tell me about your project.
Free and without obligation: 30 minutes to determine whether we are a good match. I give an honest answer — even if I am not the best choice.