When I was a graduate I often had to do proof of concepts and one had to be done by the weekend, I'd only been given it on the Wednesday. After a few sleepless nights I had it working or so I thought. On the Friday afternoon the CTO had a look at it and spotted a bug, he told me about it and I stayed in the office until about 10 when I finally managed to get some kind of fix in place. I emailed him told him I thought but was working and shouldn't happen again.

A few hours later no response I get a phone call from him screaming, shouting and swearing calling me useless and a waste of space etc. Etc. To the point I logged in desperately trying to fix the issue in a very hastily written integration and ended up having quite a major panic attack woke up on the floor and immediately went back to work. On the Saturday morning one of the senior Devs logged in and managed to fix it in the database and everything went fine in the end.

I went into work on Monday fully expecting to be fired from the way the CTO was speaking to me, I went to my line manager at the time and he just said don't worry. I left it in his
hands and things went back to normal. That call put a pretty serious dent in my confidence for years, but I learned a few valuable lessons which I stick to today.

Never work on serious shit after 6, use a second mobile for work which is turned off at 5 o'clock, properly test all fixes and always ALWAYS have someone in between graduates and senior management because honestly they can't handle the shit that's flung from above.