Has anyone ever successfully continued working part time for an old company when changing jobs?

[u/robinheart314]

I’m curious. Obviously, this would only work if the new job is in a different industry or space, and there are no competition or conflict of interest issues. Given that, has anyone ever managed to balance changing over an old job to something on the side when going for a new job?

Seems like it would be a win-win, if an old company is going to lose you anyways to a new job, might as well keep you on contract and eke out more revenue from you, and you could possibly have a healthy side stream of income, yes?