"Understanding _using_ singleflight in Go" would be a better title. This generated article doesn't give the reader a real understanding of the implementation and its various tradeoffs that you might care about depending on your workload (e.g. should the first execution to reach a key spawn a goroutine or is that allocation too much)

That being said, singleflight is a fantastic library and pattern that helps so much with p95 latency. It's a little noisy code-wise, but if you use it in the right places the gains are huge.

Also, totally agree with the below comment that recommends janos/singleflight -- start there, but most of the critical projects at my company, AuthZed, have reimplementations with tailored semantics.