Lots of people struggle to answer “tell me about yourself”, but it’s not a trick question. This is all about a firm wanting to get to know you. Who you are, where you’re at, what you’ve done, and what you’re interested in. 

Don’t assume that a firm only wants to hear about your career motivation and professional experiences, and don’t try to make your answer wholly focused on the commercial world. Doing so may well come across as you deviating from the question. Although it’s fine to discuss your interest in commercial work, I would be inclined to treat this question a little more like you would if you were asked it by an acquaintance - or a friend of a friend - in a social setting. Albeit a fairly formal social setting.

Consider talking through your life and interests chronologically, perhaps starting with something to the effect of “I was born and raised in x”, then take it from there. Talk about which university you go (or went) to and what you study (or studied). If you were educated in various countries, mention this and explain why you moved.

You could briefly summarise your work experience to date and how you’ve learned about the career. Although if you’re career changing, perhaps explain what you’ve been doing in a little more detail, as well as why you’re looking to change careers.

Discuss your positions of responsibility. If you’ve launched a side hustle, volunteered for a charitable cause or set up a university society, let the firm know. And don’t forget to mention your wider interests, regardless of whether they relate to the profession. After all, it’s often your wider interests that help you to come across as interesting and well-rounded.

To summarise, you want to give a high level insight into the various life experiences that have cumulatively helped to make you who you are. And if you do this, you may well come out with something that aligns with the interests or experiences of the person reading your application or interviewing you, which could then form the basis of a more in-depth discussion later on.