BYCHEST turns hands-on spine surgery training into a continuous learning loop in which each session becomes reusable evidence for the next practice. Trainees practice endoscopic spine procedures on patient-derived physical anatomy using real endoscopes and surgical instruments. During each session, BYLOOP records the actual endoscopic video and anchors predefined risk events to exact points on the playback timeline. These events remain available after practice so trainees and educators can revisit the same procedural moment together. Instead of relying only on memory or general observation, the trainee can identify what happened, understand what should be corrected, and repeat the same task on BYCHEST with a specific objective. Replaceable anatomical cartridges support repeated physical practice. BYCHEST therefore connects practice, persistent learning evidence, focused feedback, correction, and retraining in one reusable surgical learning cycle.