Optimizing Qt Applications: The Qt libraries are highly versatile and offer a nice API for writing applications with. From simple graphical interfaces to complex client/server architectures, Qt offers the tools to get the job done. But, just like with any other abstraction, it is sometimes not straightforward what will happen behind the scenes. This can have detrimental effects on the performance of your application, when seemingly innocent code wreaks havoc on your cache lines, hardware threads are starved and the graphical interface freezes. This talk will look at such situations, shows you how to analyze the hotspots and presents solutions to some common performance pitfalls in Qt code.