How to plan, build, and scale a mastermind? A mastermind group is a peer-to-peer group build around mentorship. Meetings are held which are aimed at solving problems, networking, and discussing trends. Aaron Walker is the mastermind of mastermind groups. Iron Sharpens Iron, is a men’s mastermind program that brings peers together who want to excel in their business, personal, and spiritual life. They’ve also started a sister program for women.