For those who are more experienced in writing performant code, I would love to see someone in action taking some piece of slow code or a library and making it run fast. I would pay good money for a series on just that!
I have heard of the tools like fprof and benchee. I have also heard advice not to trust benchmarks. Or the advice to use a profiler to identify the bottlenecks before optimizing anything.
But it still feels like a bit of a dark art to me. How does one analyze the bottleneck and test out improvements? What mental models in Elixir do we need to know X is probably faster than Y?
Maybe I’m shouting into the void here, but if you are experienced at optimizing code, next time you have to optimize something that’s not proprietary, please hit record and publish it 
