So I quit after 10 years of service to start my own company. Never had the resources or tools to put the full documentation effort in unfortunately. Trying my best for a handover. The board have started to treat me like shit, no respect after a decade of propping these assholes up. I have offered my services post employment but they are being difficult.

Just got an email and call from our data centre... they are shutting down the site and can't relocate our boxes physically due to the ip ranges in use. Only option is to migrate the sites and code to new boxes. Which means patching of db and code for newer versions.

Do I leave them with this mess since they are being assholes or try to sort it properly in my last few weeks while I also document..

By the way you spoke about them they do not look like the kind who deserve your help that way. Just know that if it was them, they would gladly throw you on the bus and not think twice about it, so just leave. If they need you they will call and then you can charge them a really nice hourly rate.

Especially what @rendevous said... notify them but just carry on with the documentation. Leave as fast as you can with your money and let those self righteous cunts deal with it.

To be honest, the phrase "propping up these assholes for a decade" doesn't reflect well on you.

You're one person. All people are replaceable. The company isn't going to go down if you leave. My friendly dev advice is get your head out your ass.

During your notice period you should conduct yourself as per normal, and document as much as you can for the rest of the team, and for those who will come after you.

You should leave an employer with the attitude that you'll be coming back one day. Do you want to be known as that helpful person who gave their all until the last minute and is welcome back anytime? Or do you want to be that jerk who had a sour demeanor and left a bunch of garbage fires in their wake and wouldn't even be welcome back in the door?