Brownfield is much harder. Working on it for a while is likely to change how you approach future greenfield projects though. There may be merit to parts of the

Brownfield is much harder. Working on it for a while is likely to change how you approach future greenfield projects though. There may be merit to parts of the codebase and/or new team's way of working that are not immediately apparent. It's also intellectually demanding along different axes to building things yourself. Parts of codebase and the way of working may also be nonsense. Potentially difficult to distinguish from the happier alternative. I'd suggest sticking with it for a little while before quitting.