I don't think that's the problem for metrics. Exometer is the go-to Erlang library, but its dependencies are a nightmare (e.g. https://github.com/Feuerlabs/exometer/issues/154 or https://github.com/Feuerlabs/exometer#dependency-management), it's essentially unmaintained, and integrating it with Ecto or Phoenix is roll-your-own. I think there is very much a need for a more modern library that plays nicely with Hex.