I'm exaggerating at the situation, but not too far off. For the past year, I've been working on an ETL app. I used Go at my last job, so I really got to hone my skills especially in regards to threading challenges. Kafka and Cassandra were also new to me.

Still, the VMs these are running on are a complete mess. Frequent, unannounced infrastructure changes, spin drives, old Java in Docker are just some of the issues that made the environment completely unstable. They chase sexy buzzwords like "big data" and "machine learning" but give us spin drive machines to do it.

I'm gonna guess side-projects. The sort of thing you throw together on a lunch break to learn a new library or tool or otherwise scratch an itch.