[javanonymous]

I've gotten 100x improvement with no code change by just adding an index in the database table. An inexperienced developer might have blamed the database and insisted on moving to NoSQL because of "web scale". If they got the chance to rewrite it, they could have pointed to the performance increase as a proof that they were right.

[no_wizard]

They really should teach benchmark training more widely in the industry. Even though I'm readily here to sing the praises of Elixir when warranted, nothing beats actually profiling end to end the workload(s) in question that need to be improved. Sometimes, it really is optimizing the database that matters most, like adding an index (or using window functions or stored procedures, as in many cases I've had in the past)

[neeleshs]

Yes, that too. Indexes and caching