Interview questions about what was most rewarding and least rewarding about your previous job can be tricky. While it's important to be honest, it's equally important to be diplomatic and smart in your response.
Match Your Response to the Job
When interviewing, always be cognizant of the job you are interviewing for and tailor your response accordingly. For example, if the last job you had involved extensive customer service telephone work that you hated, and if being on the phone doing something similar is even a minor part of the new job, don't mention it.
No matter the question, do not give a wholly negative answer. You don't want to be construed as someone who is negative about work in general. If you can think of any small silver lining related to the least rewarding part of your job, be sure to mention it. If you can't, perhaps this isn't the right issue to bring up in an interview.
If there is something about the new role or company you're interviewing with that will make the same least rewarding situation unlikely to arise, it's a good opportunity to point that out as part of what interests you about this job or to tie into your answer to the question regarding why you want to work here.
When it comes to the most rewarding experience, if you can connect that with the responsibilities involved in the job at hand, that's beneficial.
Make a List
Take the time to make a list of the qualifications the employer is seeking, and be sure the responsibilities you mention as most rewarding are a match. Make sure you explain why they are most rewarding and use the opportunity to highlight specific skills or talents and the impact you were able to have, whether it was on colleagues, clients, or the company itself.
For instance, if customer service is a major aspect of the role, you might say, "One of the most rewarding experiences I had at XYZ Company was tracking down the cause of the buggy behavior in a customer's XYZ product. I could hear the frustration in the customer's voice on the phone, so I arranged for a callback. It took two tech people, but finally, we figured out the issue. It was so satisfying to call back the customer with a resolution to his issue."
As you talk about your most rewarding experience, be careful not to brag. You want to ideally mention an accomplishment - making an annual quota, closing a deal, managing a project successfully, etc. - but without becoming boastful.
When asked about what was least rewarding, be sure to bring up something that won't be required in the new job and always end your answer on a positive note. You could frame it as something that was the least rewarding as compared to the most rewarding activities. For example, if you're switching from a customer support job to a receptionist role, you could mention that you found email communication to be less enjoyable than chatting with people, so you're thrilled this new position involves more time on the phone.
Talk About Tasks or Circumstances, Not People
Even if your colleagues or manager were the worst part of your last job, don't say that. You can discuss the way working with those people was problematic. For example, let's say you had a situation where your former colleague was especially disorganized and you were stuck doing all the documentation. One way to mention this is to say that your old job required so much paperwork that you were unable to focus on the core tasks of the job itself. This conveys unhappiness over a situation that kept you from excelling at your job instead of annoyance with a colleague.
In a perfect world, the thing you found least rewarding about your previous job was something you and your manager were able to fix. Even if they weren't implemented, it's worth mentioning any possible solutions that you came up with to fix what was wrong. Doing so will show you to be solutions-driven and positive. And just because the solution wasn't implemented at your last job doesn't mean this company won't consider it, should the same situation arise.
You don't need to pretend that everything at your last job was amazing, but an interview isn't the time to air all your grievances. Mention only the issues you can put some sort of positive spin on, whether it's a silver lining you found or a solution that was implemented.
Your response to questions about what your most rewarding experience was can also focus on solutions. You might say, "We used to have a real issue with internal communications. My boss and I launched an internal newsletter to share information, and at a holiday party, one of the executive board members mentioned to me how helpful this monthly email was."