Ret2Shell is a full-featured CTF (Capture The Flag) challenge platform built with a Rust backend (Axum web framework) and a SolidJS frontend. It manages the entire lifecycle of CTF competitions: game creation, challenge authoring (with Git-backed storage), team management, dynamic scoring (decay curves, milestones), and dynamic per-player challenge environments orchestrated on Kubernetes. The backend includes a custom Rune scripting engine for extensible challenge checkers, OAuth providers, and lifecycle hooks. It provides a REST API, a CLI client, event streaming (NATS), and a comprehensive admin web UI. Deployment is supported via Helm charts, docker-compose, or raw Kubernetes manifests. The platform handles authentication, captcha, email verification, media uploads, audit logging, and real-time communication via WebSocket/WSRX tunnels.