Interview Preparation Guide by Winston Fox

Posted on 27 May 2021


Interviews are a strange process that is not an entirely natural situation for humans to be in. For example, interviews are supposed to be a two-way street, with the company attempting to sell its position and opportunities to the candidate, and the candidate trying to sell themselves to the hiring manager, all of this interaction happening within a very short timeframe – usually 60 minutes. 


Although interviews are meant to be two way, in reality, they are heavily skewed toward the candidates making a big impression on the hiring manager and prospective firm. It may not be fair, but it is reality. So, the emphasis is on the candidate selling to the hiring manager why they are top-notch, why they are a good match for the position, team, and firm, all this within that approximate 60-minute window. 


In addition to the pressure of needing to impress and the time constraints, there is the interview psychology to deal with, such as the variety of different Interview formats, styles, attitudes, and interview skill levels of the manager or person interviewing for the firm. However, stripping away the noise you are left with the fact that the manager is looking for someone to add value to his team, and what they are trying to establish, within a short time period, is, are you that candidate that has the skills, depth of expertise, knowledge, ambition, drive, aspirations, and motivations they are looking for to join that team. Managers and firms are always looking for top candidates who can add value and upskill their current teams, but curiously, please be aware; they are also looking for reasons not to hire (more on this later).  


I have written this, hopefully, useful interview guide to help you fulfil your part in the interview and give you the greatest opportunities to nail the top roles, at top firms, with significant career paths, and paying the big bucks. You will notice that I won't talk about the firm and hiring managers part within the process, i.e. them selling you their vision, culture, career prospects, team, and projects in this guide, but if you impress during the interviews, trust me, they will pull out all the stops to secure your services! Then you get to decide if they have done enough to excite you. 

So, you have decided to look for a new position, or you have been headhunted and accepted an interview with a unique and exciting firm, which is excellent. But have you REALLY prepared for this situation? The answer is probably, no.  Typically, I would advise two weeks of interview preparation time, one week as an absolute minimum, to get you match fit for interviews. In this guide, I am going to give you some tips and exercises that will get you ready to nail the top roles, and the leading firms, at the high-end of the markets.  

First Exercise – Hit the books hard

This is the first important part of getting ready for an interview because unless you are a leading figure of your industry who is well published, well-known, or have internal references at the new firm etc then you are a completely unknown entity to the hiring manager. The hiring manager has no reference or data points to confirm your practical work experience and achievements, and they won't just take your word for it. Do not get me wrong the hiring managers are one hundred percent interested in your practical experiences, skills, depth, and achievements, and we will revisit this later. But the hiring managers are also extremely interested in the depth of your theoretical knowledge, and experienced candidates often overlook this vital section, and it is a huge mistake. Remember, you are an unknown entity to the person you are interviewing with, and they are going to ask you theoretical questions to back up your commercial/practical claims. 


For example, if you work in software engineering and will be interviewing for highly paid positions at Google, Facebook, top Hedge Funds etc, then you need to hit the books on computer science and development theory, fundamentals and best practice. Become a mini walking textbook of the areas that most hiring managers at these firms care about, i.e. software design, patterns, data structures, algorithms, distribution, memory, structuring quality code, language features etc. These can be subjects you have not read up on, or even worked on in some cases, since school/University, which makes this exercise even more important for interviews. Even if you are working heavily on some of these subjects, the theory can be very different from practical, real-world use. However, the managers are still interested in the strength of your theory knowledge and where you see pitfalls in real-life implementation.     

This exercise is crucial for pretty much any role or position, whether you are a senior portfolio manager, trader, quant, risk, product management or project management. Trust me when I say that this, theoretical knowledge, and the ability to discuss it, is fundamental, and hiring managers will be testing your knowledge, regardless of seniority! Even if you think you know a great deal about the theory, fundamentals, and best practice I would highly recommend you go back over it, it may surprise you. 

The second exercise – what have you achieved

You have a CV, and the hiring manager likes what he has read about you so far, but CV´s only contain a certain amount of information regarding your skills, knowledge, work, projects, and achievements. The interview is an opportunity to expand on and delve deeper into what you have written on your CV. 


For this exercise, grab a pen and paper, and start to think deeply about your recent work, projects, responsibilities, complexity, challenges overcome, problems solved, experience with stakeholders, things that went right/wrong, lessons learnt, the team, your results and achievements, work impact on the business. 


This exercise is essential preparation for the practical experience portion of the interview, and it is the part that most people associate with interviews, i.e. tell me about yourself? What have you been doing? what projects have you worked on? what happened? what did you do? what was the result? Etc.  


By having all this information completely and recently refreshed in your mind, you will be able to discuss everything at length and in-depth, articulately and succinctly. This is a huge selling point to the hiring manager, i.e. being able to recall this information quickly and being able to discuss it fluently, and provide detailed examples. 


Your ability to recall and discuss your practical experience and your theoretical knowledge is SELLING yourself to the manager and the firm.     


Study the Specification, skills and expertise the firm/hiring manager is looking for, and try to consider what the team/manager is trying to achieve, and based on your previous skills and experience where/how you could add value to the project or business.

Culture and character 

In addition to assessing your skills, experience, and expertise, the hiring manager, firm, and team are trying to firmly establish if they can work with you, and that you play nice. It is only human nature that we like to surround ourselves with positive, polite, and aspirational people; an interview is a time to be on your very best behaviour and display these qualities. 


Make an effort and dress to impress. We all know for a fact that looking good makes us feel good, so start with your look. This is the time to be well-groomed, your best suit or your million bucks smart-casual outfit, excellent hygiene, and a splash of aftershave or perfume. I would recommend this approach if your interview is a VC or by telephone. Deep down, you feel good, and you are in the zone! For VC´s, also be aware of what is behind and around you and make necessary adjustments as required. For VC and Telephone interviews, please make sure you have some quiet and will not be disturbed. 


It is also a fact that we are extremely attracted to smiles and positivity, I won’t go into the scientific detail about why the smile phenomena exist, but it sure does, so slap that smile on your face and try your best to keep it there! If you are not a naturally smiling person then I would recommend putting in some work on that front – it genuinely has a significant effect, not just on you but also the hiring manager or person you are interviewing with. Turn yourself into a beacon of positivity and positive mental attitude. If life isn’t going your way, projects failing, you hate your manager, you dislike your job, you have personal problems etc. – trust me, people do not want to hear it and especially not in an interview. Always find complimentary spins and angles on sub-optimal professional circumstances, there must be some, and before interview shake off any personal issues, you may be experiencing. Walk into the reception and interview room smiling and beaming. Nothing else will do. No-one hires doom and gloom.


Make sure you have done some research on the hiring manager, team, and company. There is so much information available online, and on social media, you can do quite the deep dive on most things. Knowing about the firm, manager, and even the team demonstrates you have a genuine interest in the firm, position, and the team.

Interview communication 

During interviews, try to keep your communications concise and articulate. Your previous preparation on theory and practical will help enormously here but still make a concerted effort to stay on point and answer the questions being asked, in a structured and direct way. Straying off-topic into other areas or even associated areas, can be a sign to hiring managers that you either i) do not know the answer and are trying to fluff it, ii) you are unprepared, iii) have a cluttered mind, or iv) you cannot communicate effectively.


During interviews, you must listen carefully to everything that is being said or asked of you. Under no circumstances should you interrupt, jump in, answer questions that have not been fully asked etc. Listen carefully, and asked/answer questions accordingly, once you have fully digested the information received. Do not be shy, if you do not understand the information, question, or terminology, ask the hiring manager for more detail or for the question to be reframed.


Interviews are an opportunity for the manager to discuss your work, projects, solutions, thought process, opinions, and ideas. It is very common for hiring managers to challenge any of the above during an interview, i.e. suggest your process was not optimal, wrong, provide different solutions etc. – during these types of interaction it is extremely important not to become defensive or combative. It is likely that the hiring manager is testing how you absorb and handle constructive criticism or having your ideas challenged. It is natural for people/hiring managers wanting to be surrounded by collaborative, open-minded, and optimistic individuals who enjoy learning from others. If you do not necessarily agree with the challenge, this is fine, show interest in the challenge and ask for further details to discuss (not argue) the challenge.


Throughout your interviews, be clear about what you do and do not know, demonstrate your self-awareness and willingness to learn by being open and honest. 


When interviewing, most roles have testing involved, so you need to practice and prepare. Technology and quantitative professionals are the subjects of most of the testing, so I will focus on this area. A large majority of companies now employ the use of external testing facilities during their interview process to establish a baseline level of problem-solving and coding skill, this is not personal to just you and in most cases has been internally benchmarked.


Testing by the likes of HackerRank, Codility, TopCoder etc. is the cause of much debate and argument, and I certainly have my own opinion. Still, they exist and are widely used by many top firms, so it is highly likely you will be tested in this way, so naturally, it needs to be practised.

These kinds of tests, do not reflect real-world working or projects, we know this, but they will test someone problem solving, logic and coding skills. Tests of this nature are primarily academic and timed. It is quite likely you have not worked on these problems since school or university, making it all the more critical for you to spend some time practising on these sites if you know it is part of the process!

A lot of the time, these tests are used as the first stage of the process to ensure a candidate has a predetermined level of skills before an interview process is started in earnest. I disagree with this idea, but as third-party headhunters, we do not influence client policy.


In short, if you know that this type of testing will be in the process, then you will need to practice it and get good at slamming them.

Manager empathy

I am highlighting this separately as I have now seen this countless times, and it results in no offers. When interviewing for a position, you need to commit to going through the interview process with the hiring manager, for the specific role being discussed.

This is where you need to be savvy and display manager empathy. This means a hiring manager requires someone on his team to fulfil a particular set of responsibilities, and that a candidate will have a set of skills to satisfy that need. To interview, and the smart move is to try and align your interests, aspirations, and ambitions along with what the hiring manager is trying to achieve/solve.


An example of negative manager empathy, a software engineer is being asked what their ambitions are, or, where they see themselves in 3 years? Then, the engineer answering they want to be a portfolio manager. This answer sends a negative signal to the hiring manager, that they are not interested in their position, projects, team, and are potentially using them as a steppingstone. Over 20+ years, I have seen this happen more times than I can count, and it does not end well.


There are absolutely no issues with being ambitious and driven, and with having aspirations outside of your current role and expertise, but an interview is not the right time to highlight you want to do something that the hiring manager is not offering, or cannot offer.


To extend the example, if an engineer wants to transfer to trading then the engineer should either i) interview for trading specific positions if they can demonstrate abilities/knowledge/skill or, ii) be savvy, join a good firm working closely with the trading business, build relationships, and demonstrate abilities from inside, and make an internal move after a couple of years if you can.

Your questions

Prepare your questions that you would like answers from the hiring manager before any interviews. Try not to think of questions on the fly at the end of the interview. Being prepared demonstrates to the hiring manager that you have thought about the position and firm and that you are interested, and a serious contender. This is also your opportunity to understand better the manager, team, projects, technology, culture, vision, and structure, and this will tell you if you would like to continue in the interview process.


This is a very one-sided play as most firms will no longer provide interview feedback, this is for various reasons that I will not go into here. However, I have seen extremely positive effects from candidates providing detailed analysis of the opportunities, roles, projects, and teams, and where they feel they could add value and help the manager and team, following interviews. For that reason, and if you wish to proceed, I would recommend writing an email explaining your thoughts on the interview, projects, and available position, and how you feel you would add value, where your strengths are, and how you could help the team achieve their goals.



Punctual, professional, polite, friendly, humble, positive, attitude, prepared, understanding.

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