As a hiring manager, what would you describe as the ideal answer to a
question like that? What kind of insights would you be hoping to gain by asking it?
TL/DR: Don't say it's because of your boss.
Details: I have been in a position of hiring manager and my take is this: it's a trick question intended to scan for red flags (and weed them out). Answers which imply that the reason the person left had to do with their boss, no matter how honest and well intended, could provide fodder for doubt. If the primary reason I hear from a candidate is basically, "because my boss was a total !#$#@", a number of potential red flags pop into my head:
- Is the situation really as this person is telling me? Could it be that this person got passed over for promotion, and if so, were there good reasons for this?
- Would your boss tell a different story as to why you left? Would your boss have only positive things to say about your personality and work performance?
- What kind of boss does it take to keep you happy? And what guarantees that if I fall short of your expectations, you won't spread similar opinions about me when you interview for your next job?
Since I have no way to find out, I am left on shaky ground. If I have the luxury of selecting from among several comparably qualified candidates, I will always select who I feel is a safer bet.
There are a number of reasons for this question but to me this boils down to, are the reasons for leaving things that seem relatively innocuous and generic and don't signal major entitlement/personality conflict/discipline/skillset type issues, or do they indicate either or a combination of these potential issues. Because if such issues come up at your old workplace, they might resurface here as well.
Not knowing who you are, hearing an answer to the effect of "it's the boss's fault" makes me wonder a couple of other things:
And yet they were your boss, which presumably means they had the skills and abilities that warrant them being in that position, whereas I know relatively little about your qualifications.
You just badmouthed a person who as far as I am concerned has not badmouthed you, at least to me. In spite of the apparent honesty, this also comes across as unprofessional. Even the most technical job is to at least some extent a political endeavor, and honesty is overrated when it comes to politics and professional workplace behavior. Caution, politeness, and humility on the other hand go a long way (just my personal opinion).
Part of the hiring process is trying to analyze and minimize the inherent risk involved in a new hire. What you are trying to solve for with the question about reasons for leaving last job is, are there signals that the problem is the candidate him/herself, rather than anything else they might be telling you. As such, almost any answer could be interpreted with at least some degree of suspicion, which in turn increases the risk factor.
Conversely, what you as an applicant are trying to solve for is, how do I minimize the perception of me as a risky bet, compared to other candidates? The unknowns for you are the number of candidates, pre-existing biases that the hiring manager might harbor, and how the information you divulge about yourself would be perceived and interpreted: in your favor, or against you.
Your strategy ultimately depends on how desperately and quickly you need a new job:
If you really need and want a job and have limited options, the worst advice is to "just be yourself." No -- be who the hiring manager is looking for! Assuming you can then play the part for at least as long as you need that job for (or until the next reorg/management change).
On the other hand, if you have time and are in a position to pick from among a number of attractive opportunities, then you might as well "just be yourself" and look for that elusive "mutual fit," because you can afford to. Even then, you at least somewhat need to be who the hiring manager is looking for, and the best fit in their opinion.
I hope you will find this perspective useful when considering how to handle the question about reasons for leaving previous job. What, then, are some 'kosher' reasons that strike a good balance between not misrepresenting the truth, but also not digging yourself into a hole? I would err on the side of caution here and keep things short and sweet. Keep it focused on technical and career development aspects.
"My reason for leaving was that your business better aligns with my interests and career aspirations in terms of the nature of the work and the mission and vision of your organization." - YES!
"My reason for leaving is a desire to grow my technical skills as it sounds like your are looking for someone to work with technologies XYZ, in which I already have some experience but would also like to learn more about, and I feel that this position would allow me to do that." - YES!
"My reason for leaving is that, frankly, my boss was a total idiot and I've had enough. She was an inconsistent micromanaging maniac who played favorites and generally was extremely annoying and got on all developers' nerves and I am SOOO done with her I cannot even tell you." -- NO!!!