[jjn2009]

Sticking around long enough to see a big mistake bite you is sometimes better for your growth than swapping jobs.

[mandeepj]

Definitely this. Nothing like learning from watching your solution hitting roadblocks (performance, extensibility etc) and reassessing your earlier approaches and again coming with a solution to address the newer challenges

[hinkley]

You can also dig into the problems that existed when you got to the project, and try to work out how they came to be. Project forensics is a skill set unto itself. And listen to and help people on other projects at your company. You can see how their story arc goes and where it surprises you.

An intelligent man learns from his own mistakes. A wise man learns from the mistakes of others.