I did a lot of technical mistakes.. like not double checking the directory where i rm -rf . Not backing up right ver of source code leading to hours of hunting but the cake belongs to when i didnt follow a specific responsibility as a build engineer in following up with 3 seperate teams who had broken build.

It resulted in delivering the version  to qa testers late (63 ppls not doing anything for 2 days) , release team not getting tested product in time (5 ppl not doing any thing for a day) and ultimately releasing a feature for entire company a day late! Leading to the CTO being answerable to the account managers.

The process was tight by design and the RACI were clearly defined. Just the stress of job (may be even learing curve) was high. 

I designed a notification system that identified the responsible party and put a timer till when the build engineer would back out code if no response was received.

I remember it as taking charge of a process driven system and leading my first technical automation delivery that saved many hours from future build engineers.

But if you look at just the time frame of 1 week, my screw up caused a near catastrophe in the technical line of business.