[Trias11]

Our team has essential engineer who has great potential [to become very rich person and do very creative and interesting things] and he is wasting his time and pushing on customer schedules because of his participation in stupid hackathons.

I think for some in some ways it's an effort to compensate for lack of self-esteem and prove yourself that you're worthy of praise and rewards.

[emagdnim2100]

Sounds like an opportunity to help him get those things at work and mutually benefit the engineer and the team -- or, since he's already "essential," to acknowledge that he's doing his job and not judge him for failing to give 100% of himself to the company.