My biggest mistake was not vetting companies enough when interviewing. Not catching big warning signs and thinking naively that I can work 60+ hour weeks for 1+ year with a significant amount dedicated to coding in tight deadlines - while I made most deadlines fine (the one I failed was due to no planning allocated to estimating the time to complete my team's work by product), it has seriously burnt me out & I've had to reduce my work time to ~35 hours a week (at least to no complaints)

I need to trust my instincts more & be more cautious with such big moves.