Looking back over your career, which skills compounded the most and gave you the highest return: coding ability, architecture, communication, domain expertise, mentoring, business understanding, or something else?

I think all of this is important and definitely had important impact on my career, although an early lesson I learned like 20 years ago was avoiding office gossips, focusing on what I have control on, and voting with my feet if I can't fix something that is a deal breaker for me.