Spoiler: Bob will get burned out and/or bored and quit. There's nothing you can do about this. Your job is to minimize the damage Bob does on the way out. Bob m

Spoiler: Bob will get burned out and/or bored and quit. There's nothing you can do about this. Your job is to minimize the damage Bob does on the way out. Bob may try to rewrite the codebase, or embark on wild experimental projects and somehow tie them into business needs. That's just the lifecycle of a burned-out 10x programmers. You need to enforce homogeneity and make sure the other employees (the ones you'll be left with when Bob goes leaves in a blaze of glory) are up to speed on his projects.