OpenTelemetry
The CNCF observability project provides cross-language APIs, SDKs, automatic instrumentation, a Collector, and vendor-neutral telemetry protocols.
Why use it
Online games can trace login, matchmaking, saves, and economy services end to end without committing early to one monitoring vendor.
Where it fits
Use analytics, feedback, player support, and updates to fix issues and decide what to improve after launch.
What to check
It supplies telemetry plumbing rather than an analysis UI, so instrumentation, sampling, storage, and alerts need other systems; never put raw player PII into spans.