.NET developer and architect with 20+ years of experience. I help developers apply AI agents in their own .NET codebase, through a workshop, a technical pilot or targeted guidance. Also specialised in Identity/SSO.
I'm Chaïm, 44 years old, married and father of two. I live in De Bilt near Utrecht, The Netherlands. When I'm not behind my screen, I enjoy hiking and playing board games with the kids.
What drives me? Complex problems. Genuinely, they make my day. When everyone says "that's too complicated" or "we don't have people for that", that's when the light goes on for me. I can't sit still as long as there's something left to solve.
I've been programming since I was seven. At sixteen, I sold my first software product to 35 customers. That combination of building and entrepreneurship never left.
After two cum laude bachelor's degrees (Computer Science and Mathematics), I completed my master's in Computer Science (specialisation Game and Media Technology) at Utrecht University. Since then, I've been building software for enterprise organisations: from financial institutions to real estate and pension management.
In 20+ years of enterprise software, I've learned that the hardest problems are rarely purely technical. It comes down to building the right thing at the moment it matters, alongside people who actually know the domain. That's what I'm good at.
years of enterprise software experience
paying customers on Factuur-Assist.nl
enterprise organisations served
"Chaïm got up to speed exceptionally fast and consistently made the right decisions based on his deep knowledge of .NET and SQL Server."
Cees, Software Architect at multinational
These are the patterns I see in the .NET world, and in my own daily practice:
"Copilot is switched on, but nothing changes. Some developers are enthusiastic, others want nothing to do with it. We have no shared way of working and no agreements."
"Our enterprise client demands SSO and SCIM. The deal is under pressure. Every week of delay costs us trust, and possibly the contract."
"We want to use AI seriously, but nobody has the time to set it up properly. We're looking for someone who shows it in our own code."
"Our technical debt keeps growing. Every sprint we push the complex problems to next time. Surely we shouldn't keep kicking the can down the road forever?"
I recognise that pressure. At ABN AMRO, PGGM and Van Lanschot I've seen from the inside how teams struggle when specialist knowledge is missing. That is where I can help, with a scoped assignment around a concrete technical question.
At seven, we had a Microsoft MSX computer at home. Not to play games. I wanted to understand how it worked. A year later I was writing my first programs. At sixteen, I sold software to 35 customers. Building and entrepreneurship were in my DNA from the start.
After two cum laude bachelor's degrees and a master's in Computer Science (Utrecht University), I started at DTZ Zadelhoff, where I quickly grew from developer to data manager. Then came Kadenza, where I worked on complex valuation models.
In 2011 I went freelance. It was never about earning more. I wanted to pick the problems I work on myself. Since then I've taken on major assignments at ABN AMRO, PGGM and Van Lanschot, as developer, architect and project manager. The complex, specialist challenges where teams get stuck, that's what drives me.
In 2019 I built Factuur-Assist.nl, an invoicing platform that now has 135+ paying customers. No side project. It proves I can build, launch and keep complete products running for years.
Since August 2025 I build daily with Claude Code. Two products of my own, this website. I share that experience through hands-on workshops, technical pilots and targeted guidance.
Does your team want to use AI agents more deliberately in its own codebase? That can start with a hands-on workshop or a scoped technical pilot. This is how I approach AI-native software development. For SSO and complex .NET problems, I've likely solved this kind of thing before.
"Chaïm is a true professional. One you don't want to let go from day one. Proactive is his motto. He picks up what matters and doesn't let go until it's resolved."
Robert, IT Team Lead at financial institution
Tell me about your question. In a 30-minute Zoom call we explore whether it fits what I offer and whether I'm the right person for it.