Note: The current Meta thinking is "No", they are never on topic.
Some may be appropriate on The Workplace, see their guidance.
First and foremost, any career advice questions need to relate directly to software development; general career advice questions with no relation to software development or where software development is a minor facet of the question are off-topic. A good way to test this is to ask the question, "Would the answer to the question be materially different if a non-programmer answered it?" If no, the question should be closed as off-topic.
(This aspect is discussed in Dealing with “What are some good types of pickles for programmers?” type questions.)
Beyond that, the general rule of thumb should be whether the question can help others in a similar situation. If the circumstances surrounding the question are too specific to the question asker such that there is no way to generalize and answer the question, they should be closed as too localized.
Applying that rule should put a theoretical limit on the amount of ways the question "My job is X, what should I do?" can be asked. Questions that have similar set of circumstances to already-asked questions should be closed as exact duplicates.
Finally, if there isn't something pointed being asked in the question, and the asker is merely using Programmers.SE as a means to vent about whatever annoyed them at their job that day, it should be closed as not constructive.
If, and only if, a career-advice question passes those three tests, should it stay open.
Examples of career guidance questions that should be closed:
It should also be noted that most, if not all, of the other Stack Exchanges have elected to consider their versions of "help my exact situation"-type questions (gaming recommendations, code reviews, proofreading, etc.) to be off-topic on the basis that a Q&A system does not lend well to the necessary discussion to tease out all the details to fully answer the question. I don't see why Programmers.SE should be any different.