My first gig out of school was a .net monolith with ~14 million lines of code; it's the best dev environment I've ever experienced, even as a newcomer who didn't have a mental map of the system. All the code was right there, all I had to do was embrace "go to definition" to find the answers to like 95% of my questions. I spend the majority of my time debugging distrubuted issues across microservices these days; I miss the simplicity of my monolith years :(