I watched the introduction to this video and thought: "Wow, someone should tell this guy about yak shaving." But after watching the rest, their tools are super

I watched the introduction to this video and thought: "Wow, someone should tell this guy about yak shaving." But after watching the rest, their tools are super cool. The profiler where you can see performance frame by frame and then jump back in time to the specific invocation of an expensive function blew my mind.