Being able to confidently say infront of the CEO that everything you implemented is working just fine, while their business is standing still because another software company fucked up almost everything, having tried everything to blame us for the errors, reminds me of why I’m doing this shit.

I've been in a similar blame situation with a client where another third party tried to blame us, but that's definitely not why "I did not that shit".

I did that shit because I did the best I could with what they asked us to do. There were 3 teams on the project - 2 from our consultancy and another third party. The other team and other party started first but were way behind so we're working late nights and over weekends. We came in as the AWS integration layer between the 2 teams at the point of freaking out about being late. We calmly told them that we don't work evenings or weekends, we do our work in billable hours. We estimate correctly. We finished 2 weeks ahead of schedule, implemented fun "nice to haves" for morale and helped the other 2 teams by adding things to our layer.

Even after all of that, I don't attribute any blame to any team and I still think of it as one of the most interesting and fun project that I've worked in in my 6 years of consultancy