Steam Achievement Notifier (SAN) is a feature-rich Electron desktop application that monitors Steam and RetroAchievements unlock events and displays highly customizable on-screen notifications. It leverages the Steamworks API for real-time achievement tracking without requiring an API key, and integrates with RetroAchievements via emulator log file parsing. The application provides extensive customisation – multiple notification presets (consoles, Steam Deck, custom), per-type themes (colors, fonts, icons, glow, masks, positions), screenshot overlays, streaming overlays for OBS, Discord webhook posting, game completion timer, and a diagnostics troubleshooter. Architecture is multi-process: a main process handles window management and IPC, a renderer process displays the settings/customiser UI, a worker process continuously polls Steam for game state and achievements, and a RetroAchievements worker monitors emulator logs. Communication is event-driven with well-defined IPC channels. The project includes Rust native modules for keypress simulation, HDR screenshot capture, and high-performance process watchers, bundled as precompiled binaries. The codebase is actively maintained with regular releases, comprehensive localization (25+ languages), and detailed inline documentation (tooltips). While architecturally sound with clean separation of concerns, some modules (e.g., sanhelper.ts) are monolithic and tightly coupled to the application's config and UI, which may hinder isolated reuse. The translation files are large and duplicative, requiring coordinated updates across languages.