I would not be able to pick one most difficult question in a job interview as I think it is a tie between “What do you consider to be your biggest weakness?” and “Where do you see yourself in 5 years time?”
The weakness one is a hard question to tackle because the whole purpose of a job interview is for a candidate to sell themselves which usually means talking about positive experiences or describing themselves in a positive light. But this question is asking you to describe a weakness – something that is negative.
Almost all interviews contain this question or one that is similar as it is a good way for the prospective employer to assess how well you can critique yourself, and whether you have the ability to recognise problems – after all, no employer wants an employee who remains unaware of weaknesses as they will never be able to strengthen them.
In my opinion the best way to answer questions which ask about your weakness or any other negative aspect, is to turn the negative into a positive. So in this case, select a moderate weakness rather than something which could pose as a big problem or one that could jeopardise you getting the job. Once you have selected it, describe it in a way that makes it clear that you acknowledge it and understand why it is a weakness but go on to say what you have done to rectify it. This way you are cleverly answering the question but steering it in more the direction of describing it as a past weakness which is under control.
The “where do you see yourself in 5 years time?” question is difficult because it is one of the only questions where it is difficult to predict what they want to hear? On the one hand you want to show that you are ambitious and that you see yourself progressing but on the other hand you don’t want them to think that you won’t stick to the job at hand for long enough, or worse, if it is not aligned with opportunities that they are likely to offer, they may think that you will quit and go elsewhere which will put them off from hiring you.
I think that you can follow one of two strategies when answering this question. The first one is to be honest, so if you have your career plan mapped out, be honest and hope that your answer demonstrates something that they want to hear. This is slightly risky because it may sound as though you have it planned and are therefore relatively inflexible, but could also work in your favour as they can see you as being someone who is focused, driven and a forward thinker. It may also strengthen your position in portraying how you have chosen this career because you are passionate about it rather than because you couldn’t find anything better during your job search.
The second strategy could be to be very vague, something like “Ideally I would like to be a specialist in the area that I work in but I know that circumstances may attract me to different opportunities so I am not committed to any ideas for my future career plans”. This could prove that you are flexible and willing to adapt which could make your employer feel comfortable that you are someone who would stay for a long time and possibly carve out your career within the company. On the other hand it may show a lack of focus. From experience I have found this strategy to be the most successful but you have to judge the situation accordingly.