Ask HN: Autonomy, Mastery, Purpose -- how does your work give it to you?

Daniel Pink's Drive is frequently cited here for its mantra of "autonomy, mastery, purpose" as the principal motivators for people's work. I've given this some thought and have to say that I've hardly ever been in a situation where any meaningful attention was paid to these.

I'd like to ask for HN's wisdom on this. How have you been able to find autonomy, mastery, and purpose in your work? (I happen to be asking this from an employee perspective, but I won't mind hearing from startup founders as well, especially if you can tie in to how you provide this for your employees.)