I have a love/hate relationship with Prometheus. If I had no budget for metrics its likely the thing I would reach for, but I’m dying for someone to open source a ‘next level’ metrics system (something like Monarch or Circonus but free).
But woe betide the team that has to run it as a service. Not that other metrics systems are better but Prometheus can be brutal in that space.
As a ‘squad level’ tool its really good. After that it gets hairy fast.