Yes, sometimes there are emergencies where working long hours isn necessary, and if you're well rested before, you can still be productive, if not optimally so.

Yes, sometimes there are emergencies where working long hours isn necessary, and if you're well rested before, you can still be productive, if not optimally so. But these are rare exceptions. If they occur regularly, it's a sign of shitty management and a shitty company you need to get out of ASAP. Especilally if you're told it's normal and something to be proud of As for your examples >ship or lose customer x. shitty customer, will probably use low quality resulting from it as an excuse to withhold payment. Get a better customer. >Promises are made that can't be kept by humane working hours. Shitty management, no excuses >Things break days before a huge demo. Probaby because of bad code written by someone working late. >Someone gets sick. Nobody else can do their job? Shitty management > You are in an arms race with a well-funded competitor. You probably won't win it with code that breaks all the time.