ThreatSims One Platform is a cybersecurity event hosting platform designed for organizing Capture The Flag (CTF) competitions, recruitment assessments, training events, and classroom sessions. The platform supports both team and individual participation formats with dynamic challenge containers and flag management. The platform includes real-time scoring and leaderboard functionality, anti-cheating mechanisms, and event collusion logging. For recruitment purposes, it offers candidate comparison tools, performance metrics, and manual evaluation capabilities with report submission features. Training events can be configured with scheduled challenge releases, flexible timing controls, and adaptive learning paths that match participant skill levels. The platform provides hands-on technical labs for instructor-led classroom sessions with individual and group assignment capabilities. Event organizers can issue digital certificates to participants with custom designs, event metrics, and online verification through QR codes and credential links. The platform has been used to organize over 40 events across 10+ countries with more than 15,000 participants, including events at DEFCON, SANS, and various security conferences. It includes content protection features, integrity checks, and scalable infrastructure to accommodate events of varying sizes.