Go is a very performant language, so, normally you don't need to optimize it at all. But what happen when you need it? This talk is a walk through some techniques and tools that you can use to squeeze that last drops from your functions. We are going to see tools like pprof or go benchmarks, and explore some of the results. We are going to explore other topis like escape analysis, function inlining or the garbage collector, that all of them can affect the performance of your application.