Overseerr is a full-stack self-hosted web application for managing media requests in a Plex ecosystem. Users can search for movies and TV shows via TMDB, submit requests (including 4K variants), and have those requests automatically pushed to Radarr/Sonarr for download. The application also tracks media availability by scanning Plex libraries, syncs Plex watchlists, and provides a comprehensive notification subsystem supporting Discord, Telegram, Slack, email, webhooks, and web push. It includes user management with granular permissions, quota enforcement, issue reporting, and a highly customizable discovery page built from TMDB-driven sliders, genres, networks, and studios. The frontend is Next.js (React) with Tailwind CSS, SWR, Formik, and react-intl i18n; the backend is Express with TypeORM on SQLite. The project is feature-rich and has been widely adopted, but the README states it is superseded by the Seerr community fork, and the codebase relies on several aging dependencies (Next.js 12, React 18, Tailwind 3) and a hardcoded TMDB API key. Despite this, the code is well-organized with clear separation between API clients, entities, routes, and UI components, and many parts are written with solid engineering patterns such as a base external API client with caching/rate limiting, a template-method scanner base class, and a clean notification agent interface.