Understanding Phoenix.Endpoint AsyncWith v0.3.0 released: the asynchronous version of Elixir's "with"

The curious case of the query that gets slower the fewer elements it affects

A blog post that shows off a real life performance bug and we tried to fix it, failed, and then fixed it for real. It shows off benchee as a benchmarking tool in use on a concrete case together with features like inputs and also the newly released tagging, saving and loading. Also goes a bit into SQL and EXPLAIN ANALYZE, multicolumn indexes and friends. Hop along for the ride.