PostHog is Django + Vite + Celery + plugin-server, backed by Postgres, ClickHouse, Kafka, Redis, and Temporal in Docker, fronted by an Envoy-style proxy at . The dev stack runs in detached mode under so the running processes are inspectable from this session via the MCP server. Browser MCP servers ( , ) drive the UI; nothing about this skill ships its own driver. For : get the app reachable so the user can drive it. Success = serves and the core units are . Do not chase crashed migration units, do not seed data unless asked. For : build (Vite HMR handles this automatically for frontend; backe…