Dmitry Trofimov - Profiling the unprofilable When a program is not fast enough, we call on the profiler to save us. But what happens when the program is hard to profile, like for instance the Python Debugger? In this talk we're going dive deep into Vmprof, a Python profiler, and see how it helps us find out why a debugger can be slow. Once we find the culprit, we'll use Cython to optimise things. ----- Profile is the main way to find slow parts of your application, and it's often the first approach to performance optimisation. While there are quite a few profilers, many of them have limitations. In this talk we're going to learn about the new statistical profiler for Python called Vmprof that is actively being developed by the PyPy team. We'll see how it is implemented and how to use it effectively. We will apply it to an open source project, the Pydev.Debugger, a popular debugger used in IDE's such as Pydev and PyCharm, and with the help of Cython which we'll also dig into, we'll work on optimising the issues we find. Whether it's a Python debugger, a Web Application or any other kind of Python development you're doing, you'll learn how to effectively profile and resolve many performance issues.