Hey, I'm Marcin.

No sponsors, no SEO filler. If it's here, I've run it in production or broken it trying.

I have been writing software for a living since 2007. Java first, then .NET from 2010. Somewhere in the middle I spent a few years on mobile, back when shipping to Android and iPhone meant writing everything twice and arguing about which SDK was worse.

Most of the years since have gone into enterprise web applications. Real users, databases older than the team maintaining them, and migrations scheduled for a Tuesday night because that was the only window anyone would sign off on.

Lately it has been .NET and Azure, with a long run of Azure IoT. For the past while I have been head down in AI and LLMs, which is most of what ends up on this site. I am still sorting out which parts of it are genuinely useful and which parts are demo-ware, and I would rather write from that position than pretend the question is settled.

I spent years leading teams, which meant code review, hiring, and the same architecture argument at slightly different volumes. Moving a large codebase to .NET Core taught me more about how an organisation actually works than any design document ever did.

These days I work for myself, which suits me better than I expected it to. I used to teach Java as well: Spring, Hibernate, the patterns everyone eventually reinvents. Explaining something to people who are about to go and use it badly turns out to be decent preparation for writing things down.