Konrad Kokosa is a Polish .NET specialist and the author of Pro .NET Memory Management (Apress) — the canonical reference work on the CLR memory model and garbage collector. He runs Dotnetos, a .NET training company focused entirely on the deep performance side of the platform.
His CourseFlix listing carries two Konrad Kokosa courses: .NET Memory Expert and Async Expert. Material is paid and aimed at senior .NET engineers working on performance-critical applications who need to understand the CLR at the level the framework hides from most developers.