Tempo's a backend/sink for traces, but if you click through to the Tempo docs and find out how to generate tracing data[1], you learn that you have two options: OpenTelemetry, which they recommend, and Zipkin, which they do not recommend.

[1] https://grafana.com/docs/tempo/latest/getting-started/instru...

Tempo is a traces server. Prometheus is a metrics server.

Grafana, the same company that develops and sells Tempo created a horizontally scalable version of Prometheus called Mimir.

OpenTelemetry is an ecosystem, not just 1 app. It’s protocols, libraries, specs, a Collector (which acts as a clearinghouse for metrics+traces+logs data). It’s bigger than just Tempo. The intention of Patel seems to be to decouple the protocol from the app by having adapters for all of the pieces.