Dokku is a production-grade, self-hosted Platform as a Service (PaaS) that manages the full lifecycle of containerized applications. Its architecture is a plugin-based monolith orchestrated by a core Go binary, where every feature (builders, schedulers, proxies, storage, config) is a self-contained plugin that hooks into lifecycle triggers (plugn system). It supports deployment via git push, archives, or Docker images, and can schedule containers locally via Docker or on Kubernetes clusters via its k3s scheduler. The codebase demonstrates high craftsmanship in its plugin architecture and state management. The `common` plugin provides a robust property store, parallel execution engine, and safe command execution utilities that are used across all plugins. The `scheduler-k3s` plugin is a standout, featuring a custom Helm diff engine for previewing infrastructure changes and complex Helm chart generation for Kubernetes resources. The `storage` and `docker-options` plugins contain well-structured parsers for their respective domain-specific languages. While the core Go code is well-structured and heavily tested (Go unit tests, BATS integration tests), the codebase has medium technical drift. The extensive use of shell scripts for plugin triggers introduces fragility, and the Kubernetes scheduler hardcodes specific versions of external tools (cert-manager, KEDA, Traefik) that require manual updates. Despite this, the project is actively maintained with frequent releases, comprehensive migration guides, and a clear deprecation policy, making it a strong example of a long-lived open-source PaaS.