Below 50 mentees, ad-hoc mentoring works. Above 50 it breaks — not because mentors get worse but because the matching, scheduling, and accountability overhead grows non-linearly.
The operating model that scales: structured matching by specialty, weekly cadence with calendar integration, rubric-based feedback after each session, and a clear escalation path when matches do not click.
Without structure, mentor quality varies wildly per relationship. With structure, the floor lifts and the ceiling stays high.