Every developer should be confident that their code is efficient and safe to run in production. But it can be hard to get started. What tools to use? What do the graphs mean? What to look at first? In this talk, we will analyse and optimise the performance of a simple PHP application. By demonstrating how to use some of the excellent open source projects such as xdebug, xhprof or ApacheBench, I hope to give you a good idea of where to start with analysing and optimising your PHP code.