Is this a polished enough answer to, "Why do you want to leave?"

Frankly, I would consider that a bad response. Almost all you are doing is complaining.

I'd suggest that instead you cut the rest and lean into this (assuming that this is the sort of job you're applying for)

my background is in systems administration and infrastructure engineering - that’s what I worked hard to build my career around, and that’s where I want to focus and grow.

[This is really what motivates me, and my current job isn't offering me opportunities to grow in this space]

I don't know how many times you've interviewed people who talk negatively about their past experiences, but it's really something that turns most people off - whether interviewing for new colleagues, housemates or even first dates - just don't do it. Talk about what makes you stand out, not what about what makes you sad.

"The role has changed significantly from what I was hired for, and what I really want is to focus on systems administration."

It's short, understandable, neutral, and gets you onto talking about systems administration which is where you want to be. You're not assigning blame, you're hinting that there's probably a larger story, but that you're going to be professional and neutral.

I always regard this kind of question as more of a professionalism test - is this person going to badmouth people, are they being forced out of the company, etc. I'd not be looking for the full reason, but something I can match with everything else. So if someone says "Oh, I feel I've outgrown this role" and it's been a year, I'd be concerned - it's either way too easy a role, or they're lying, for example.

Ideally you want to spend as little time as possible on this question. Discretion is also a good quality in a system administrator, and you've got a chance to demonstrate it here.

it's not unreasonable that they'll press you a bit here, in which case "my current role ended up merging with a desktop support role, and I really want to focus on system administration" is pretty reasonable (if this is what happened)

I think that'd be understandable to anyone with an IT background, and is a good filter if they want you to do the same in this role.

This is a question that usually means something considerably more constrained than "please tell me why you are looking for a new job". The two underlying meanings, for the asker are:

You are a person who will leave a job for a better one. Please reassure me you won't leave this one if I hire you

or

You are a person who isn't enjoying their current job or excelling at it. Please reassure me you would enjoy this job and excel at it

I would not mention the money at all. Changing jobs for money reasons is often seen as greedy and selfish and gets held against you. I would also not mention having too much uncompensated work piled onto you. Focus on what you want in the new job:

my background is in systems administration and infrastructure engineering - that’s what I worked hard to build my career around, and that’s where I want to focus and grow. I want to be in an environment that allows me to expand my expertise rather than dilute it.

Also be aware that your interviewer may not see much difference between "systems administration" and "running and managing desktop and frontline support" so hanging your whole argument on this distinction may make you seem overly picky and pedantic. If there are specific aspects of this job (either in the job description, or that have been mentioned so far in the interview) that give you a warm feeling you will be able to follow your preferred path, connect back to them specifically now. That's one of the reasons it's not a good plan to rehearse a two-minute response to a question. Ideally your response weaves back into what has already been discussed and builds on the conversation you've been having.

To use your own words:

"I want to focus on systems administration and infrastructure engineering but my current role has shifted heavily into desktop and frontline support."

That puts the focus on where you are going and gives a non-negative reason for wanting to move away from your current role. Plus it's short.

I like the very last part of your response:

I’m looking for a role where my skill set is fully utilized, my growth is supported, and my compensation reflects the work I’m doing.

This is all you need to say. Short and sweet. It doesn't sound like a complaint, but an optimistic next step in your career. Don't add ANYTHING.

I agree to what morsor said in the beginning of the answer: This is way too long of a response. It will be best to keep it short and simple, and as generic as possible (without mentioning anything that can even remotely portray your current employer in a negative light). You can summarize the statement as below:

"I was hired as a Principal Infrastructure Engineer to support and manage the company server environment.

After the company eliminated its MSP, I absorbed those responsibilities but my compensation was not revised as per the elevated roles and responsibilities, based on the value add and market comparison. Also, my role has since shifted heavily into desktop and frontline support, limiting my growth in systems administration and infrastructure engineering, where I want to focus.

I am now seeking a role that fully utilizes my expertise, supports my professional development, and offers a fair compensation for my contributions based on the value I add to the organization."

Usually brevity is best with these things.

If you're leaving because of pay, you can say you're seeking better career prospects.

If the place is chaotic, you can say you're seeking a fresh challenge.

Most employers, perhaps somewhat bizarrely, don't want to be acknowledged as competing successfully with their competitors on pay, or don't want to hear pay suppression as a reason for dissatisfaction at the existing employer (perhaps because they indulge in it themselves, except when recruiting externally).

This often leads to interviewers being told crazy fictions unfortunately.

Usually the result simply comes down to whether an employer wants a new bum on their seat. They're unlikely to press further questions to oblique and generic answers when they want to hire, whereas they may find lots of questions if they don't want to hire (the answers you give to which are immaterial, the fact of asking them shows how they are already minded doubtfully and simply seeking confirmation).

Some employers are intentionally seeking fresh meat themselves, so it shouldn't always be assumed that an unsuccessful interview meant your answers could be improved. If they know they're backfilling a boiler room position with an appalling manager and where your pay will be permanently frozen, they don't want someone who has just come from that and is already primed to react against it.

Just don't use the interview as a forum to rattle off a long list of bog-standard grievances.

I wouldn’t say any of this save for a quick summation of your current scope of responsibilities and what you’re looking for out of your new role (“because this is where my interests truly lie”). This isn’t the only question they’re going to ask you and you’re covering far too much ground and including a lot of irrelevant details.

This is a bit of a crude analogy but try thinking of it like a first date. Your date isn’t interested in learning all about your ex. If they ask about previous relationships, it’s because they’re interested in what the answers reveals about you.

Interviewers are assessing whether you’re a good fit for the company, not only your skills and background but also your personality. From their perspective, your tale of woe and lament reads like a requirements spec on how to avoid failing you as your current employer has. They’re not interested in that. They want to know what you can do for them.

It’s perfectly reasonable (and encouraged) to ask tough questions of the interviewer to ensure that what they’re offering aligns with your expectations. It’s also good that you’re reflecting on your past experience and using it to inform your expectations for the future. Everything you’ve written is valuable and important—for you. It’s just not important for the interview.

I've done my share of hiring and being hired. I've also worked in doing the same kinds of jobs that you're interested in.

My first response (and that's all you're going to get from your interviewer), was negative but not for most of the reasons others have given. It struck me as a type of qualifications and history review. Too "looking back" for me.

• Foremost, it doesn't really answer the question of "why?". I guess that's why you got some nice suggestions of how to do that.

• Yes, it's too long (much too long) and focuses on your current job in too much gory detail. So, in that sense I'm agreeing with others.

• You are being interviewed by your future! Do yourself a favor and focus on that (instead of the past). Such as:

"I really love the challenge of infrastructure engineering and systems admin and am anxious to apply myself in a more challenging environment. I believe this company is a place I can do that! Does that match with your idea of the job?"

.. to be followed up with:

"I'd hope/understand? that this company/you are in need of someone who can ....."

"When I converted the Annex to a full-blown domain system the work was challenging and satisfying!"

etc. etc. in bite-sized chunks.

Show your enthusiasm for the future you envision with them! Have you heard of the "30-second elevator speech"? That is very much my point here for you.

I think your real question was in one of your comments:

I never got the whole - it's unprofessional to acknowledge bad behavior in a constructive way.

It’s unprofessional because it’s unhelpful to the task at hand, which is deciding whether you are going to work at that company.

It’s unhelpful to the interviewer, because if it’s true or not is both unknowable and irrelevant, and it’s unhelpful for you because it isn’t going to elicit an “our managers and co-workers are worse” or anything else indicating that you shouldn’t work there. Whether you are a lying piece of shit or a long suffering saint, it’s not a reason to offer you the job and it’s not a reason for you to take this job instead of one elsewhere.

You and the interviewer(s) are meeting to decide three things: are they willing to hire you, are you willing to work for them and finally, can you come to a mutually satisfactory agreement on compensation.

Negative comments, no matter how “constructive” aren’t helpful, they don’t show you in a good light, at best they reflect badly on your current employer.

It’s like being asked about your hobbies and saying you are a little league coach, and complaining about the umpires being incompetent or biased. Little league coach, +1, bad mouthing the umps, -5.

You may wonder why they are asking the question at all, and the answer to that is that are looking for something positive, something that makes you desirable to them or them desirable to you. If it’s neutral, then no harm no foul. If it’s negative, that’s a mark against you.

But since you did ask: Your prepared answer is both too long and too negative. Player One's answer is too negative, there’s no reason to say that the current employer isn’t offering something, just say what you are seeking. Put everything in positive terms, keep it short, be prepared to expand.

My first reaction is that it is a bit long. Whether it actually is, depends on what your desired outcome is.

If their question 'Why do you want to leave' really is just them being polite and you already have secured your next job, the last sentence will actually do (without mentioning compensation) - as they probably just want to check a box on an exit-interview-form. Furthermore - if they know you 100% are moving on - they won't really care what could make you stay; your (now lengthy) explanation would just seem as weird criticism that should have been fielded before leaving.

However, if you are willing to stay, the explanation does in a somewhat constructive way signal that the situation is fixable and exactly how. Whether it will work, almost certainly depends on many other factors way more important than the exact contents of the explanation - like budget, the skillset of other employees, whether your desired role is one they need and so on.

I don't. These are a few of the reasons why I love my current job, and why it would be a very difficult decision to leave:

• The people, especially my current boss. He and I have developed a strong relationship based upon trust and respect.
• The work is really engaging and fulfilling.

I am, however, strongly considering this position because:

[list your reasons]

If you cannot get to a place mentally and emotionally where you can speak positively about the position and the people you are leaving, then why would anyone hire you? Your interviewer is making a decision about you, and comparing you against every other candidate. Every answer you give will help him make that decision one way or another.

Your goal is not to accurately describe what is wrong with your current decision. Your goal is to convince your interviewer that you are the answer to his prayers. In other words, he doesn't want to know about your current job; he wants to know about you. Are you positive and upbeat and someone he wants to work with, or are you someone who will bitch and moan about how unfair everyone else is?

If you slander your ex-employer at the job interview the hiring company is going to start wondering if you are going to slag them off like that when you leave.

Probably not the thoughts you want the other party to have when you are busy with courting ritual that is the job interview

I'd just focus on where I'm going. (that's the advice I got from my mentors in the past) - this helps to keep you out of that negative energy.

I've enjoyed working with I enjoyed it for the past years and grown a lot (can mention some of your accomplishments), now I'm looking for my next adventure where I can and and I think your organization is amazing because it aligns with what I'd like to accomplish in the next phase of my career.

I was hired as [...] to [....] and run point on [...]

I wouldn't recommend focusing so much on past intentions. Those just don't matter. Intentions are often able to be perceived differently, which make them feel more fickle, and trying to cling onto a preferred old perspective may make you sound more inflexible. Instead...

About a year in

So that means there was a change after a year. Just describe what you did during the first year before the change. You might want to avoid timelines, just leave it vague by explaining what you did, and that you enjoyed that.

I absorbed all of that work - saving the company $40K per year. Despite that significant increase in responsibility, I didn’t receive a salary adjustment, and after two years, I only got a 3% raise - the same standard increase given to everyone.

This quoted text has two issues.

One is it makes you sound averse to work. Even if you are, you don't want to appear to be so averse that you lack the professional tact to at least not unnecessary convey the obvious truth that many people desire not needing to work as hard. Pointing that out doesn't seem to do you many favors.

The other is being dissatisfied with how they handled paying you. It makes you sound greedy. If you're going to be greedy, maybe try to ask for a larger amount of compensation. They might just think that is what you are used to because they do pay you that, because you are worth it. But don't sound like someone who is always dissatisfied with money (even if you are). The goal is to not give off the unprofessional vibe.

Beyond that

This sounds like, again, trying to re-inforce what I just recommended against.

my role has shifted heavily into running and managing desktop and frontline support, which I’m now handling company-wide alone.

And here is the key crux of how I recommend you make this more positive. Do not complain about the current situation, and how dissatisfied that made you feel, and especially don't complain about being understaffed. It doesn't make you look prestinely superb.

Instead, just point out that you wish for something in your future, such as more time working on servers instead of desktops and frontline stuff, and your boss has laid out a different path for you going forward. Indicate the positive desire about what you want to see going forward, and that you hope the company you are going to will supply that for you.

If they can, then this is starting to sound like a positive future with them, and the only real negative scenario is the potential future at your old company which isn't going to happen anyway, so there isn't much negative going on there. So if they can provide you with the future that you described as positive, then all seems great. (And if they can't provide you with that, then maybe you are better off losing that opportunity rather than winning that opportunity under false premesis that delude you from the truth. Because, then, at least you know your near future isn't positioned to be a great future with them.)

my background is in systems administration and infrastructure engineering - that’s what I worked hard to build my career around, and that’s where I want to focus and grow.

Careful with this. In the sense that your background has well prepared you for these tasks, this can be a benefit. In the sense that you are trying to lock yourself in to only what pleases you, this gives off the vibe of being inflexible. Even if you feel like you don't want to be flexible, the inflexible vibe feels unprofessional and isn't really want you want to be strongly giving off.

Right now, I feel like my skill set is diminishing instead of developing, and I want to be in an environment that allows me to expand my expertise rather than dilute it.

Don't say this! Don't say things are diminishing! Lowering skills is terrible. You want to have zero terribleness that they can detect during a process of application review and/or interviewing.

With all increases being based on an outdated salary

"outdated" sounds like a negative jab. Avoid.

due to this structural shift in my duties, there’s no real path to long-term alignment.

The first part sounds inflexible, and the second part sounds so negative. If there is no real path to long-term alignment, let that just be implied by the fact that you are seeking to align with someone else. Focus on the positive (desired future). Don't dwell on the dead-end past/current.

At this point, I’m looking for a role where my skill set is fully utilized,

"utilized more"... you don't sound like you want to work to your full capacity where you are tapped out. (Appearing to have infinite unused capacity, always ready to grow, may be better.)

my compensation reflects the work I’m doing.

Obviously you want this. Mentioning a desire to focus on desired compensation suggests a focus on benefiting you more. While you may want that, the briefer you can make them think about such a point (which may be a less desirable aspect from their side of things), maybe the better. (Keep in mind that hiring may be based on emotions... how they are feeling.) The topic of compensation must come up at some point. Bringing it up again and again won't server you as well.

In summary: chop off the negative, and to help do so, chop off discussions about compensation, unpleasant current situations, and unpleasantness of past situations. Just focus on a different desired future, and how you matching up with the server-type work you want will be a great match for both you and the upcoming employer.