As someone who has written an APM profiler for multi-threaded, async .NET web applications I can attest to how hard it is. There are actually a few ways to do a

As someone who has written an APM profiler for multi-threaded, async .NET web applications I can attest to how hard it is. There are actually a few ways to do async type methods in .NET and supporting all of them was even more fun. Begin/End older style method delegates async/await with normal tasks async/await with TaskCompletionSource (aka fake tasks) and of course completely custom ways in 3rd party libraries Crazy hard profiling magic, FTW! FYI, I wrote the .NET profiler for Stackify (http://stackify.com http://stackify.com) as part of our APM solution