Uptime Kuma is a self-hosted, open-source uptime monitoring application that periodically checks the availability and response time of services (HTTP, TCP, DNS, databases, Docker containers, and many more) and sends alerts via 90+ notification providers. The system is a monolithic Node.js/Express backend with a Vue 3 SPA frontend, using Socket.IO for real-time updates and SQLite or MariaDB for persistence. It provides status pages, maintenance windows, certificate/domain expiry monitoring, and a Prometheus metrics endpoint. The architecture follows a plugin pattern for monitor types and notification providers, both built on base classes, and includes a condition evaluation system for advanced alerting logic. The codebase is well-structured with clear separation of concerns, extensive tests (unit, integration, e2e), and active community contributions.

Dockge is a self-hosted web application for managing Docker Compose stacks. It provides a graphical interface to create, edit, deploy, and manage stacks composed of multiple containers. The application supports managing multiple Docker hosts (agents) from a single interface, enabling centralized control of distributed Docker environments. Key features include a web-based terminal for container access, real-time updates via Socket.io, stack lifecycle management, and extensive customization through settings and environment variables. The architecture consists of a Node.js/Express backend with Socket.io for real-time communication and a Vue.js 3 frontend built with Vite. The backend handles Docker interactions, database operations (using SQLite or MySQL for metadata), and agent management, while the frontend delivers a responsive UI with internationalization support. Data flows involve the frontend sending user actions to the backend via Socket.io, which then interacts with the Docker daemon (local or via agents) and persists stack definitions as compose.yaml files on disk. The system emphasizes a file-based approach for stack definitions, ensuring portability and transparency. Dockge demonstrates strong engineering practices through its modular design, including isolated components for settings caching, terminal management, rate limiting, and an extensible agent system. These components exhibit low coupling and high reusability, adhering to principles of separation of concerns and maintainability. The application also incorporates modern development practices such as multi-stage Docker builds, automated CI/CD, and comprehensive test coverage (though not detailed in the provided summaries, the presence of CI workflows suggests testing efforts).