Joining my current company and saving a relationship with a key client from the brink of termination. The previous engineer on the account had overpromised and

Joining my current company and saving a relationship with a key client from the brink of termination. The previous engineer on the account had overpromised and under delivered... in a rather big way. Not only that, but he also managed to misconfigure the enterprise automation software we use and accidentally delete the customer’s entire network share, then managed to get one of those cryptolocker viruses on the share after it was restored from backups, prompting a second restore. Regardless, the customer was pissed as hell and was on the verge of firing us. After I was hired and put on the account (which I knew going in), I spent two days taking stock of all the shitty stuff the previous engineer had built, deciding what could be salvaged and what had to be discarded. Then, for the next two months, I went over the original contracts and built (or rebuilt) the originally promised system. I would basically work for 10 hours everyday, 7 am to 5 pm, then write an extremely detailed report to the customer explaining what I had done that way, which would take another 2 hours. For the first week they ignored my reports. Then the CFO started taking interest, first by nitpicking, then asking questions, then praising. The rest of the customer’s team slowly came on board as well, especially once I started delivering the bits that were user-facing. Today this customer is our flagship account, and has helped us land many other large accounts. But those two months were probably the most stressful of my life, not just because of the technical challenges but also due to having to simultaneously navigate the tricky political situation.