Endurain is a self-hosted fitness tracking service that operates much like Strava but allows users to have complete control over their data and the hosting environment. The application's frontend is built using Vue.js 3 and Bootstrap CSS. On the backend, it leverages Python FastAPI and stravalib for seamless integration with Strava. The MariaDB database engine is employed to efficiently store and manage user data, while Jaeger is used for basic observability.