BetterDiscord is a client modification for Discord that injects into the Electron app to provide a plugin and theme system, custom CSS editor, addon store, updater, and developer tools. The architecture is a monolith within the Discord client, structured as three packages: injector (main process), preload, and renderer. Key entry points include the main process (`src/electron/main/index.ts`), preload script (`src/electron/preload/index.ts`), and renderer initialization (`src/betterdiscord/index.ts`). Data flows involve IPC between main and renderer, webpack module interception for patching Discord's React components, file system access for addons and settings, and GitHub API for updates. External dependencies include Electron, React, Monaco Editor, lucide-react, and react-spring. The codebase is well-structured with TypeScript, has tests, and exposes a comprehensive API (`BdApi`) for plugin developers. However, it heavily relies on Discord's internal webpack modules and hardcoded module IDs, making it brittle and requiring frequent updates as Discord changes. The project is actively maintained with recent commits and responsive issue triage.