A full stack developer is either a back end developer that has no business writing front end code but does it anyway, or they’re a front end developer that has no business writing back end code but does it anyway.
Or they’re perfectly capable of doing both because they’re at a startup that’s years away from running at scale or having to worry about performance and security.
Warnings? We’ll come back and address those later. Maybe once we’re feature complete. Or maybe shortly after that.