I make sure I'm aligning my personal technical interests with the kinds of projects I work on for the company, so work feels more like a fun puzzle to solve rather than slogging through tedium. Generally I don't work late into the evenings, but sometimes a problem is really just that fun to solve, and I enjoy spending time on it. Other times, projects may be less interesting, so I work fewer hours, letting myself rest. Burnout is real, and it sucks, and I avoid it at all costs.

My employer really just cares that I get my work done, not how many hours it takes to do it. If I'm getting "meets all" or "exceeds" in my yearly ratings, then I'm meeting or exceeding their standard, and we're both happy.