In my case, I ran into an old coworker on the street that was working in a space that sounded interesting, and now I've been working with freight railroads for

In my case, I ran into an old coworker on the street that was working in a space that sounded interesting, and now I've been working with freight railroads for 3 years after spending ~15 at giant, well-known tech companies. But it depends on what you mean by interesting? We build SaaS products for railroads. Day-to-day, that often means writing software that looks similar to other industries. APIs, web interfaces, relational databases, cloud hosting, etc. I wouldn't say every line of code I type is particularly interesting. But when I'm feeling annoyed at working on some mundane feature, it's easier for me (relative to previous positions) to step back and remember that the overall space is full of interesting people, history, and different methods and processes that I would've otherwise never known about. And I still have that some of that childhood fascination with trains.