PostHog

PostHog is a product analytics platform that bundles several tools a product team usually buys separately: event analytics, session replay, feature flags, experiments, and surveys. The argument for bundling is that these tools answer related questions and are more useful when they share one event stream. The analytics core is an event pipeline. A product sends events with properties, and the platform builds funnels, retention curves, and paths from them. Session replay records the interface alongside those events, so a drop-off in a funnel can be watched rather than only counted. Feature flags and experiments read from the same user identity, which is what closes the loop: a flag can gate a change, an experiment can measure it, and the funnel shows the result. The platform is published as open source and can be self-hosted, though the self-hosted deployment is a heavier operational commitment than the hosted service.