I went from hacky hobbyist programmer to working on core business logic for a startup that eventually the whole company would rely on. I was mostly a one-person team at the company, and I kept a lot of my bad unscalable tendencies from making small fun projects. No formal testing, very little documentation, hundreds of “TODOs”, breaking API changes without really telling anyone, no QA process, no monitoring/reporting, etc.

It all came to a head when my employer was demoing some software that used my API and none of what they were trying to show worked because of multiple unrelated bugs in my code, causing us to lose this very large client. I somehow kept my position, worked with other departments to formalize QA processes, and started regularly communicating with the API users.

Before I was just making software for nobody with 0 stakes, the reality of having actual people, entire revenue streams dependent on my code being reliable didn’t fully register. At my previous (and only other at the time) employer I was basically a paid seat filler. I spent a lot of work hours making personal projects, it felt like going to work and getting paid to make hobby code.

I’m glad I was able to learn from the experience and it didn’t put me out of work or anything