I have been in this situation myself, but my former boss has a conscience, as it turned out. My wife and I were on a vacation that was timed to celebrate an important birthday. I had spend days during the preceeding week training up two people on my team, and maybe one or two others, on various processes and contingencies. Yet still, when push came to shove, I was asked to get online to put out a fire. Luckily it only took an hour or two. A few days later I was surprised to find $1000 bucks deposited into my account from my boss as a thank you.

This system that I had hacked together, built out and maintained, kept on growing in size, complexity, attributable revenue and potential compliance liabilities. Within the year, I had to call the execs into a meeting to drive home the point that this wasn't a tenable way for us to operate. Everyone had known as much but it was still a tough pill to swallow. I let them get too spoiled at a huge cost to my own mental health.

I had to paint a dire picture to make my case that the system had to be rebuilt from scratch in order to be integrated into the main infrastructure. I ended up leaving a few months later as the rebuild was nearing completion. A couple of months down the road I was surprised to learn that they were still using a part of my system alongside the rebuild. Apparently their architecture couldn't support an algorithm that this component had relied on.

What a mess!