SkyWalking

SkyWalking is a full-stack APM platform — distributed tracing, metrics aggregation, service topology maps, and alerting in one Apache project. It auto-instruments Java, .NET, Node.js, Go, Python, and Rust services without code changes, then visualizes the entire call chain across your microservices.

For teams running microservices who want free observability without Datadog's bill ($23+/host/month), SkyWalking delivers. Jaeger is tracing-only — you need Prometheus + Grafana alongside it. Signoz is the newer alternative with a modern UI and OpenTelemetry-native approach. Datadog and New Relic are the commercial benchmarks.

The catch: SkyWalking is Java-heavy — the backend runs on Java, and the best agent support is for JVM languages. The UI is functional but not beautiful. Documentation is inconsistent, with some parts clearly translated from Chinese. Setup complexity is non-trivial. And in 2026, OpenTelemetry has become the standard for instrumentation — SkyWalking's proprietary agents feel increasingly like a divergent path.