I’ll echo what @tristan said, that we’re working on how the Spandex team can integrate and/or combine with the OpenCensus-BEAM project, because I think that’s the spec that makes the most long-term sense. I’d say that if you’re looking to add something to an app today, maybe try adding OpenCensus and file issues for any trouble you having (both documentation and technical issues), so we can figure out where the gaps are.
I still haven’t taken the time to figure out what that experience is like myself from an Elixir app, but if decide that you’d rather use Spandex, we have a fully-worked example that you can use to see what’s required to integrate Spandex with the commonly-used frameworks (Plug, Phoenix, Ecto, Datadog). Check out the links to the diffs in the README to see the exact changes you’d need to make in your app. Spandex only supports Datadog though, so that might be a deal-breaker for many environments. It wouldn’t be hard to add a new back-end, but no one has contributed one yet. We currently use Spandex at Bleacher Report, and it interoperates seamlessly with Datadog’s official clients for Ruby, NodeJS, .NET, etc.
