Orchestrating a mass clean-up of the questions in the career-development tag is something we could do as a first step: vote to close and/or delete questions as appropriate. Some might be worth migrating to Programmers, but it'd have to be judged carefully and on a case-by-case basis.
It's pretty clear that these questions are off-topic on Stack Overflow now en masse, so it should be fairly easy to close and remove (where needed) these questions in preparation for removing the tag itself.
Many of these questions may be on topic for other current and upcoming Stack Exchanges sites. I suggest closing questions, but not deleting them or removing the tag. This will keep it easy for users of other sites to browse these questions for ones worth migrating. Unless you're familiar with the policies of the site in question, you probably shouldn't vote to migrate yourself.
1 No downvotes, several upvotes to recent questions about this.
2 Arbitrary, but working on the same questions has less risk of votes being wasted.