Nobody warned me the first job would mostly be reading a decade-old codebase instead of writing new code

Pictured building features from day one. Reality has been mostly archaeology, tracing a bug through four services and four different eras of the same team's coding conventions, none of which are documented anywhere current. It's not what I expected at all, but I've started actually understanding the system in a way that greenfield work probably wouldn't have taught me this fast. Still adjusting the expectation though. Anyone else's first few months look nothing like the bootcamp portfolio projects?