About

I'm Eelco Hillenius. I got a Commodore 64 when I was twelve, and within days I cared less about playing games than about making them. I taught myself to write them, and ran straight into everything that comes after the first idea: you need tools of your own to build at any real scale, you hit optimization problems that force you to understand what the machine is actually doing, you end up rigging an art pipeline so the whole thing doesn't collapse under its own weight. That was the hook, and about thirty years later it still is.

I studied Business Informatics, which packed in plenty of computer science — programming, databases and SQL, how computers actually work — alongside the analysis and product skills that decide what's worth building in the first place. Most of what I'm good at lives at the seam between what a business needs and what software can actually deliver.

Long before PIE, I took over Apache Wicket, a component-based Java web framework, in its early days. Its original creator had shipped a first version and was moving on, just as we'd chosen Wicket at Topicus over the usual options of the time, like Struts, and committed to getting it to production quality. I pulled together a team from Topicus and the project's early community contributors and led development for years, adding the things Wicket became known for, like first-class Ajax support and its models layer. We eventually brought it into the Apache Software Foundation, which was its own kind of education, and I co-wrote Wicket in Action along the way.

These days I build software products under Chillenious LLC and lead PIE, an open-source framework for delivering and authoring online assessments. I operate as much as a product manager as an engineer now, which suits me: the parts of the job I care about most are deciding what to build and how to organize the people building it. I still write code most days.

This blog is where I think out loud about that work. Three things keep coming up: agentic coding and how sharply it's changing the economics of software decisions, software architecture for systems that have to survive for years, and how to organize development teams so they can move without falling over. The opinions are mine and usually strongly held.

Chillenious LLC is a one-person company in Sammamish, Washington, building its own apps and open to selective consulting. The fastest way to reach me is email: eelco@chillenious.com. I'm also on LinkedIn.