Company soft killed the product, everybody left, they didn't hire anyone to replace. We went from 20 engs to 3. Worst codebase ever made by ex FANGs hotshots who thought they understood something about system architecture. Very "clever" and complicated. Data consistency issues happening everyday, likely due to misuse of messagging queues. Chargebacks being ignored and mailed in physical letters every month. A couple of millions going through the platform every year.
My task was to run a team of mostly juniors maintaining and adding features to that mess.
I had no clue what that codebase was doing. We just left things as they were, fixing fires as they came. Nothing too bad happened. Slowly built a leaner replacement for some components. We simplified things over time and we even rebuilt some of the knowledge of the old platform, which helped with the daily outages.
The issues started happening not as often. Eventually. I moved on from that company, removing again a big chunk of knowledge. Over time I've heard tales of other people coming in and rebuilding that knowledge, over and over.
The platform is still standing.
