OpenTelemetry (abbreviated OTel) is an open source application instrumentation standard, hosted by the CNCF, that provides common APIs, SDKs and tools to produce and collect traces, metrics and logs, whatever analysis tool is used afterwards. It was born in 2019 from the merger of the OpenTracing and OpenCensus projects.
Its value: you instrument the code once, then send the data to the tool of your choice (Datadog, Grafana, Honeycomb, New Relic…) without redoing everything if you switch. A central component, the collector, receives the signals, filters them and routes them to one or more destinations.
It is supported by most languages, frameworks and observability vendors, and serves as the foundation for cloud-native monitoring architectures.
Why it matters when hiring
OpenTelemetry is a good marker for an SRE or Platform Engineer who built observability rather than consumed a vendor's. Ask how the candidate propagated trace context between services and how they kept volume under control (sampling). For a product developer, knowing how to add a useful trace is enough.