1.  What are the common attributes of consultants who excel and advance quickly in your company?

This question can often lead to valuable information. For instance, quant skills are more important at some firms than others for junior consultants. Asking that question shows that you are interested in performing well if you are hired. And it also gives you a chance to assess if you would really be a good fit.

2. What will I be expected to accomplish in the first 3 months / first year with the company?

Similarly to the first one, this question shows that you've got drive and want to perform at your best. It also gives you a chance to learn more about what you will really be expected to achieve in your first few weeks and months as a consultant with the firm.

3. If I make it to the next round of interviews, is there anything you'd recommend I try to improve on before coming back?

You should only ask that question if you think your interview went well. There's no need to ask that question if you already know you've messed up the maths part of the case for instance. But if you ask it at the right time, you will both show that you are willing to hear feedback and you will also collect useful information to prepare for your next round.

4. How is your company different to other consulting firms in this country / city? I've asked people around but I'm interested to hear your perspective.

Your interviewer will often ask you Why McKinsey / Why BCG / Why Bain? At the global-level consulting firms are quite similar - the differences really start showing at the office-level where the culture and type of work can vary. Asking that question at the office-level usually reveals useful information to help you decide between different companies.

5.  I'm interested in Energy consulting. Can you share what you know about this area of the company?

You should obviously replace "Energy consulting" by any topic you are interested in here.

This question is really powerful for two reasons. First, it differentiates you vs. other candidates and shows you've really thought about what kind of consultant you want to be. In a given region / city one or two firms will typically dominate a particular industry. It's a good idea to find out which ones it is for the industries you are most interested in. Second, this question can lead to follow up conversations. Your interviewer might not be able to give you the full picture and might decide to put you in touch with people from the practice you are interested in. This can turn into a massive win for your application!

6. What are the biggest opportunities / challenges facing the company right now?

Large consulting firms like McKinsey, BCG and Bain are pretty resilient. But their strength will vary by office / region. It's therefore a good idea to understand what the internal narrative about opportunities and challenges is. For instance, you could try to find out what new areas / practices the office you are joining is investing in at the moment.

7. What do you enjoy most / least about working for this company?

If you have already found out everything you wanted to know about the company and office you are interviewing with it can be a good idea to ask slightly more personal questions to your interviewer. Who doesn't like to talk about themselves after all? Asking them what they enjoy most / least about their firm is a good way to get their perspective on the company you'll be joining.

8. I'd be interested to hear about your most challenging case so far and what you have learned.

This question is similar to the previous one. Getting your interviewer to tell you a bit more about their experience at the firm can't really hurt!