> if there was a platfom with a powerful enough query-language for it (e.g. give me all requests that go through 4 services, have errors on service 3 but not 4,

> if there was a platfom with a powerful enough query-language for it (e.g. give me all requests that go through 4 services, have errors on service 3 but not 4, and are associated with userId 123 on service 1) Datadog has a new feature for querying the whole trace call graph that they seem to be testing out. Sounds like precisely the thing you're describing.