What is distributed tracing and how do you implement it with OpenTelemetry?

In a microservices architecture, a single user request touches dozens of services. Distributed tracing follows that request across all services, recording timing and metadata at each step.

OpenTelemetry (OTel) is the vendor-neutral standard for instrumentation. Implementation:

1. Add the OTel SDK to each service.
2. Services automatically propagate a traceparent header in HTTP calls, linking all spans.
3. A collector (OTel Collector) receives spans and routes them to your backend (Jaeger, Zipkin, Tempo, Datadog).
4. You can now visualize the full request path, identify slow spans, and pinpoint errors.