What are the most common performance related mistakes that you have seen projects make when developing Java applications?
The biggest performance related mistake, and it happens a lot, is not having the performance requirements defined early enough in the project. When you are designing software, you need to understand just how fast it is going to need to go. Having a hard number makes it possible to leave out optimizations that are intrusive, make the code much harder to maintain, or just take a lot of effort. If you have a soft number, like “as fast as it can go”, then you have to make an effort to make these kinds of optimizations. I know that it is often difficult to understand these numbers early in the project, but it is just as important as any other requirement. The later you put that requirement in, the harder it is to account for. Probably even harder than most requirements, since performance affects the entire systems, not just a part of the code, like a new feature might. This is one of the reasons that you need a design that lets you adapt to changing performance requirements. JPT: Which chan
