All the while management is breathing down your neck and asking 'why isn't it ready yet'.
Once the thing is shipped, then all the important people come out of the woodwork, who were surely there all along, 'supporting' you from behind the scenes, there are photo ops and important people shaking hands. If they feel particularly charitable, then you might get a seat at the table. There's talk of spinning up a team around the product, and people fall over each other to get to lead it.
But the thing is, most likely they don't need your expertise any more, not really, once everything works, you don't really have a negotiating position as a dev. They get some cheap juniors to fix the bugs and add the missing feature niggles - hiring 3 juniors might not even be cheaper, the point is management does not have to depend on you, they can play their human resource games.
'But only I can fix that complex race condition, that popped up half a year after development' - well if it was good enough with the bug for people not to notice it for half a year, it's going to be good enough for another half, until the new devs can fix it.
This applies to ambitious feature requests as well - if the code's good enough that the contract was signed, the business requirement was met, they can just kick the can down the road until they can fix it.