My experience: we were working long hours (until 2am) trying to solve problems which were unsolvable. The end goal could not be reached. Second to that, engineering is a rather thankless job. You get nearly no feedback that your work is helping someone or helping to achieve something (as opposed to say, a doctor where the feedback to your work is very direct and tangible). What I found is that burnout isn't a particular event or a moment in time, its rather like a scale where on one side are all of the bad things in your life and on the other are all the good things. The mind can take a lot of stress, but if the scale tips too far toward the bad side the entire balance gets thrown off. It took me around two years to get out of it, but what helped was to become hyper aware of everything in my life and if it was a net positive or net negative event, commitment or activity. I tried my best to cut out all of the negative (not my job, however). I like my boss, my colleagues and I enjoy what I do. It was a temporary phase that tipped the scale in the wrong direction but we managed to regain balance in the end. Its been around 4 years since then, I'm still in the same job (with a slightly different perspective) and totally fine now. My takeaway from all of it: make sure to look at other areas of your life to find the source/solution to your burnout. For example: sport, eating well, sleeping well, taking time to clear your mind (meditation, walking, sport, whatever works for you), social activities, activities with your partner/spouse, family. This is of course anecdotal and worked for me, may not apply to everyone.