Understanding a big company project in Java [closed]

Question

what is the best way to understand a big company project in java?

Answer 1

There's a nice podcast/interview with Dave Thomas ("The Pragmatic Programmer" Dave) about this topic, here.

He calls it "software archaeology".

For many different reasons organizations frequently lose control of their code bases. Knowledge gets forgotten, people leave. One could very easily mistake the code base for an archaeological concern were it not for the fact that mission critical applications built upon it keep chugging along until something needs to be modified or enhanced and then suddenly you have a vat of source code that no one understands but that has become the most important thing in the world overnight.

There are very few short cuts for coming to terms with big vats of code. Generally, one has to balance the quest for "understanding it" with the pressure to make pointed pragmatic changes to "complete the mission".