Technical Interviewing 101 | Hiring Experts Weigh In On How To Nail Your Technical Interview

By BrainStation August 15, 2017

Planning to interview for a technical role? Whether you’re a Computer Science student or grad, training to become a Developer or Software Engineer, or a Hiring Manager looking for technical roles, we’ve rounded up hiring experts from Shopify, INTERSECT, Hired, Wave and Wealthsimple to dive into how you can nail your next technical interview.

The Panelists

Stergioss Anastasiadis

Director of Engineering, Shopify

Stergioss leads Shopify’s Engineering team in Toronto and is responsible for building the platforms of Shopify that enables commerce across many channels like Facebook, Pinterest, and Amazon. Stergioss is passionate about developing people, building innovative product experiences and creating a diverse team with a 50-50 split of women to men composition.  With over 25 years of experience, Stergioss has worked with several startups, companies of all sizes and at various growth stages,  and has built teams across geographies. Prior to joining Shopify, Stergioss was the Engineering Manager at Google.

Nahim Nasser

VP Engineering, INTERSECT

Nahim is the VP of Engineering at INTERSECT, overseeing all product development. He has a proven track record of leading engineering teams to successfully deliver challenging software products for clients such as eBay/Stubhub, Travelocity, and 500px.

Formerly a technical director at INTERSECT, Nahim’s focus has shifted from leading individual teams to managing the entire engineering body. He specializes in crafting world class teams and leveraging processes to increase operational efficiency with an emphasis on quality and longevity.

Lisa Winberg

Senior Talent Manager, HIRED

Lisa Winberg is the Senior Manager of Talent at Hired, the opportunity network that matches outstanding people with the world’s most innovative companies. Lisa leads a large team of career coaches who help candidates prepare for interviews everyday and we have helped thousands of candidates navigate their searches. She also works with companies to help them improve their interview processes to be perceived as “employers of choice.” Lisa loves nothing more than empowering individuals to reach their personal and professional goals and is on a mission to help everyone find a job that they love!

Ash Christopher

Senior Director of Engineering, Wave

Ash Christopher is the Senior Director of Engineering at Wave, leading platform and operations engineering on a quest to build Wave’s next generation of financial service products. He has spent his years at Wave focused on problems of scale and sees technology as the means to increase developer productivity and efficiency.

In past careers, Ash rebuilt G Adventures eCommerce website, and developed monitoring, communications and safety systems for oil rigs at Pason.

In addition to exciting challenges at Wave, he recently entered a whole new adventure as a new father.

Karney Li

VP Engineering, Wealthsimple

Karney Li is the VP of Engineering at Wealthsimple. In this role, he leads an engineering team that is disrupting the financial investing world. He’s been integral in bringing a complex micro-services architecture to life, designing a system for scale, and has made key technology decisions including the adoption of Ruby, Rails, and React Native to meet the technology needs.

Prior to leading Wealthsimple’s engineering division, Karney spent 10 years at Amazon as both a Software Engineer and Development Manager. His career has spanned their offices both in Toronto and south of the border. Karney looks forward to sharing his lessons learned from his rich and varied career.

technical interview

What is your approach towards interviewing? What is the technical process?

Stergioss: The two entry points into Shopify is either a referral or application on the website. Our interview process are broken down into two big phases; cultural, we really emphasize that there has to be a really good fit with how we want the individual to work with the teams, and then interviews that are focused on problem-solving, technical deep dives, pair programming and a technical life story – those are usually done in two phases. We like to keep the cycle pretty short, within a week to 10 days have an engagement and answer so that they have a quick evaluation of how they fit or not within the team and you get feedback on the end, either an offer or how to improve.

Nahim: For us, we have four interviews, three back-to-back technical interviews and we like to score things by putting things into four buckets. The first bucket is raw computer science and software engineering talent, breaking down data structures, algorithms, do you have the programmer’s tool belt, do you know how to break down problems, things of that nature. The second bucket is domain experience, if you’re coming in as a Senior Engineer and you’re claiming to know how certain systems work, we’re vetting that. Then we start to look a little more at leadership and grit, dive a bit deeper into your personality, and then we dive into how you make decisions, which is more on the behavioural side. How do you deal with situations that we’ll throw at you for example. We weigh all four of those buckets equally.

Lisa: Just so everyone knows, 7-10 days is very impressive and not industry standard. Typically what we see with the majority of the companies that we work with is that there are multiple stages. Many start with a phone screen with a recruiter, usually some sort of take home technical assessment followed by an onsite interview that would combine technical and cultural interviews. The tip I would give you all is that if you’re getting into an interview process, it’s OK to ask what the process looks like to manage your expectations and prepare.

Ash: At Wave, our interview process starts with a take home test. The philosophy we have is we can bring you into an interview with our problems that you’ve never seen before, but we want to make sure that we’re giving you the best opportunity to show us your best self. So we take products or features we’ve built ourselves, lowered the scope and give it out as a take home project that takes 2-3 hours to complete. The idea is when you come in for you in-person interview, we’re going to pair-program on the code that you wrote and the domain that you understood so that we’re really able to assess your talents. When you come in for your interview, we’ll do three technical interviews and one cultural interview. The first interview is a pair programming exercise where you work with two of our engineers, and they’ll ask you to modify your program or add a new feature, and the next one would be more of an architecture type interview, it would be on the whiteboard where we ask you to think how this system that you designed might fit into a greater system; can you communicate that on the whiteboard? Did you truly understand the architecture? The last one focuses on engineering values, how you will work in a team environment and what sort of value drivers you have as an individual. When we’re up against a deadline and everyone is working really hard to meet commitments, are you going to work with the team as well or are you the kind of person that leaves at 4, who cares, or are you going to provide support and work well with your other team members. Wave has a set of value drivers that dictate how we approach problems, and we want to see what your value drivers are and how they apply to Wave’s and whether you’re a cultural fit or not.

Karney: Wealthsimple’s process is pretty straight forward; generally a recruiter will reach out and explain what the company does, and if you’re interested they’ll schedule a phone interview over a coder pad. A coder pad is an interactive console that allows you to write code and the person on the other side can pair with you; that is to see if you can get past the problem and have a working solution. Most of our interview questions are designed to see if you can understand abstract problems, do some problem solving and solve them. The purpose is to see how the person things, how they approach the problem.That’s really what the job is, we’re developing applications and we want to see how they would act if we gave them feedback and encouraged them to change their solutions. When we’re on site, we do two more coding interviews, a whiteboarding interview and a cultural fit interview. I think the nice thing about the process is there’s no correct answer; it’s really about understanding the candidate and understanding how they work, how they think through problems and if it matches how we work. People come from all walks of life, they can be computer scientists, artists, political science students, etc.


There’s a lot of components to these interviews. What are some of the most useful mechanisms you’ve found to understand how people think?


Ash: The piece for us that has given us the most information is how people react in the face of adversity; if you’ve given someone a solution and someone challenges it, how do you react to that is really telling about your personality and what we could expect if you worked on our team. If you get incredibly defensive, that’s probably not going to work very well on our team. If someone can quickly empathize and modify their thinking or justify why they’re going to stand by their original thinking, that’s a big identifier if someone’s going to be successful.

Stergioss: The level of seniority plays a role in what signals we’re looking for; for someone who is junior, the focus is on can they understand the basic coding constructs and how that comes across when they’re doing their paired programming. On the flip side, for someone more senior being able to hit on the area they’ve worked on and that they’re passionate about that we can discuss in detail and I might learn something I don’t know and compare it to something else and get some pros and cons, it really depends on the seniority. On the technical side, the combo of pair programming and problem-solving are key in some of the decision making that we make.

Ash: How does a software engineer break down something super ambiguous? What types of questions are they going to ask to make constraints? You can see what questions take them where and watch them take a journey from something super ambiguous and watch that solution evolve into something that could go to production. That’s something we try to observe and simulate, whether it’s on a whiteboard or through coding, we want to see the journey of going from something ambiguous all the way to the end.

Karney: I’ve been on the fence with whiteboarding for many years. Some candidates do terrible writing code on a board because it’s unnatural; I think it’s refreshing to make people write code on a computer, but it poses other challenges. Now that code actually has to compile and work so it can be frustrating if there’s a syntax problem or they’re not able to convey the ideas as well anymore. So there’s definitely pros and cons of the medium and how people are being interviewed. From what these people have said, it’s very true; no matter what medium you choose, there’s going to be some adversity. You’re either going to be stuck using something you’re not used to, or in an environment that you’re not used to coding in. Some people like to code with headphones on for example, so there are all of these psychological issues you need to overcome. I’ve probably done well over 700 interviews in my life now and everyone struggles with it; it’s very rare that you find someone who is excellent at it, and they are people who interview a lot.

Lisa: It really depends on what you’re trying to assess. Whiteboarding is a bit of a controversial topic, and it has a lot to do with the person who is running the interview and what they are expecting to get out of it. So, if that person is expecting for a right answer that they believe is the only answer, it’s a really stressful and challenging environment for the candidate and not natural or something that normally happens and doesn’t create a great experience for that candidate. So something for candidates to consider is that an interview is a two way process. You’re both evaluating each other, so if you go into an environment and they don’t explain to you what they’re asking and you’re getting a vibe that you’re bombing, this might not be the right environment for you. A lot of companies don’t expect the “right” answer, they’re looking at the process to see what it would be like to work with you.


How do you want people to prepare for your interview?


Stergioss: In my experience, I’m really looking forward to hearing what they’ve accomplished in their career. The intention is always to position a problem in a way where we can hone in on areas you have experience with and be able to convey solutions based on your background, so it’s not going to be something foreign to you. Similarly to the pair programming, you bring your own laptop, you program in the language that you want in the way you’re comfortable with and have been doing, so we try to put you in a position so you can succeed based on what you know, and not try to reinvent things that put you in uncomfortable situations. We want to validate that what you say you’ve done is visible in the interview.

Ash: You can focus on learning all of these algorithms and data structures, but there’s the preparation of who is the company, what do they do, and how do I fit into the company. I’ve probably done 300-400 interviews with Wave, and I still meet people every year who don’t truly know what we do. So don’t overlook the basics. Also, identify your passions and see how they align with the companies that you’re applying to. There’s nothing worse than someone who isn’t excited, or they’re at Wave because they just need a job. So when the passions are aligned there’s a much better sense of rapport and the interview process is much more comfortable.

Karney: People in HR can really be helpful. We’ll prepare you and tell you how the interview will look, who you’ll be interviewed by, what to brush up on, and I think that’s a really good indicator. For Wealthsimple, we want to see how people solve application tech problems. You can get sample questions from HR, and often times your best friend is that person in HR who is trying to see if you’re a fit. Glassdoor is a great resource where you can access interview questions, too.  

Lisa: You get better at interviews by practice and develop that confidence. Ultimately that is going to be what sets you apart, the way you compose yourself during the interview. Not just technical practice (there are lots of websites out there where you can brush up on the basics like interview cake and github), but also preparing for the behavioural and cultural interview. A lot of times people will cram for the technical piece and forget about the other aspects of the interview. A little secret about behavioural interviewing, they’re pretty standard: tell me about a time when…if you Google it, there’s probably about 20 different variations of what you could be asked. So I would encourage everyone to take your resume and pick different experiences from each of the different roles and decide what you’d want to highlight; what you’ve learned and how you approach problems. Make sure you know your resume inside out, so when they ask the question, you’ll be prepared with good stories about yourself that you can draw on. Practice and continue to develop that skill-set so when you go into that interview you feel calm. It’s like exercise, the more you do it the better you get.

LinkedIn is your friend. Know who is interviewing you, it’s expected! Look into their background so you can ask better questions that are tailored to their background. Show that you’ve done your homework.

technical interview

What is your perspective on the two-way dialogue between the interviewee and the interviewer?


Ash: In a nutshell, I respect candidates way more if they are asking questions about us and vetting us. We want candidates to have a lot of options, so if they are vetting us that says something to a degree. One of the questions I sometimes ask candidates is what is their evaluation criteria for selecting an opportunity, and how well they articulate that tells me a lot about them and gives me insight on how to close them.

Stergioss: When I get asked questions that are meaningful about the context of what I work on every day, I always start thinking about how their career fits into the organization so it engages me with respect to where they want to go.

Karney: A lot of people over index on talking through the problem. Often, that two-way dialogue is pushed too far in a play-by-play, but that’s not what people are looking for when they mean “communicate” in an interview. Rather we want you to communicate ideas and show that you can implement the ideas.

Lisa: With regards to the dialogue, the questions that you ask can really set you apart. I don’t think it’s a secret, but something I always tell candidates is people like to talk about themselves, and when you ask questions that give the interviewer an opportunity to talk about their own experience or vision, they’re going to view you a lot more positively if you give them an opportunity to show off what they know or talk about the company.

Karney: Building a rapport is very important; ask about the individual you’re talking with. Sometimes at the end of the interview, we’ll ask what the top thing they discovered in this interview was, or what’s the most exciting thing you learned about our company, to assess where their head’s at and what is resonating with them. It’s not just the company interviewing you, it’s also you interviewing the company. You want to make sure you’re using your time to discover the interesting pieces of the company and discover if it’s the right place to you. Don’t ever feel so desperate that you have to take any job; this is your opportunity to evaluate the company as well.

Lisa: How a company treats you throughout the interview process is very telling. It’s in the company’s interest to make you feel if you were to get an offer that you would want it. If you reach out and don’t hear anything, you ping them and still don’t hear anything, and then two weeks later they reach out if you’re really passionate maybe give it a chance but if they show they don’t care then consider looking at other opportunities. You don’t want to go in with a feeling that you’re desperate and will take anything.

Karney: Even candidates who aren’t successful at getting a job, they are great at recruiting for us as well. If someone had a great experience through our interview process, even if they didn’t get a job but they were excited, passionate, 6 months later they can come back and they’re telling their friends about us, so it’s in our best interest to provide the best experience that we can. Our onboarding process starts when you’re applying to the company, two or three weeks before you’re doing the paperwork.


Every company has a different culture and assessing that candidate’s fitting with the culture is a hard thing to do. As a company, how do you assess cultural fit?


Ash: What I really try to dive into is understand how people learn. One of the questions I ask is tell me about the most impactful advice you ever received from a mentor, manager or colleague. I’m really curious about the answers I receive because they are telling me something they did poorly, telling me how they improved it and the result. They’re also telling me the type of individual they are and that they are open to feedback and self-learning. So that’s a really important question. Another one is how people deal with conflict. Generally speaking, we try to dive into scenarios, we give scenarios and we try to get candidates to provide scenarios, and then we’re able to extract as much information as we can.

Lisa: Culture fit can mean a lot of different things and really great companies have figured out what that means when they’re assessing for culture fit. There’s a lot of talk in the industry right now about value fit. And what that means is companies need to know what is important to them and making sure they’re asking questions in the interview that allow candidates to speak to their own values to see if there is a fit. A lot of people complain about the culture piece because it’s so ambiguous, but when you actually boil it down to what is important to us as a company, what do we believe in and what are our values, it’s a lot easier to be objective.

Karney: Values are extremely valuable to a lot of companies. If you ask a company they will tell you what their values are. Wealthsimple has 5 values that we celebrate on a daily basis and we celebrate people who exemplify them. We’re looking for people who demonstrate these values, and look at their expectations and do they align with our values. So read the company’s values and ask yourself, is this a good fit for me? I would also say that sometimes companies don’t live up to their values; so when you’re walking around the office, see if you can see examples of their values and see if you can see counter examples too. It gives you a lot of insight into what kind of company it is.

Stergioss: At Shopify we have 6 values that are pasted all over the walls, if you don’t know what they are coming into the interview then you haven’t done your homework. Understanding continuous learning, self-awareness, adapting and being passionate should resonate and influence how you conduct yourself in the interviews. It’s not rocket science, it’s expected.

Ash: The value interview is the hardest one to conduct; you probably need your most senior interviewers doing it. The people on our culture team put together value drivers, which is a hierarchy of your values. In every system of values there is a certain point where you may not live up to those values, so we think of it as a system and identify from the core outwards a heuristic for making decisions. This is what we dig into, let’s try to identify what the individual’s value drivers might be. If you have a family and children, of course, you’re going to put children at the centre of your value driving system, but you’ll also work late, which means your children are pushed out of your value driving system and not your core values. Your values don’t have to be the same as ours, but we want to see if your value system aligns in general with our value system. I don’t think it’s fair that if we say if you don’t live up to all 6 of our values then you’re not a good fit; we want to just know what sacrifices you’re willing or not willing to make and make sure that aligns with us.

Lisa: The hiring team isn’t just thinking about you and your values, it’s how you’d fit in with the team. Most companies will have you meet with potential colleagues which is a great opportunity to get to know them in the interviews so you can ask tailored questions. If you have the chance to do this, ask questions about the culture, the work environment, what it really means to work there. They’re often the ones who can give the best insight as to whether the company walks the talk of their values.

Nahim: I think it’s really important to be aware of the stage of the company. If you’re looking at younger startups, some of them may not have figured out values yet and it may be toxic for them to figure that out at that early stage. So just have that grain of salt in the back of your mind, consider what stage a company is at as context when you’re interviewing with these companies.


What the decision-making process look like internally? What does that regroup look like? And if it’s a yes, what does that look like and if it’s a no, what is the significance of the rejection?


Ash: At Wave we are heuristic based, which means we’ll create a rubric that talks to engineering values, core values, value drivers, and we think about the shape of the candidate; we’re not saying “unless they score ⅘ they aren’t a fit”, we look at the overall fit. You have to find the right balance and get a diverse set of people. If there’s an opportunity for someone who has the drive, hustle, right values but they score ⅖ on the rubric, it doesn’t mean they won’t get hired. We look to see if there’s a way we can find a fit; we can teach people various skills. The hardest thing to teach is empathy or finding a way to win in the face of adversity. The completed rubric then gets sent to a committee who wasn’t involved in the interview process to avoid introducing bias around gender, seniority, race etc.

Lisa: At HIRED we have panel interviews and independently everyone needs to fill out a scorecard following the interview. We list competencies and ask people to comment on a scale on how the candidate performed, and then we have a debrief run by our talent acquisition team. They run the debrief and give people the opportunity to discuss and debate the candidate’s merits. It’s an opportunity to see how people view a candidate from their focus area and how the candidate is a fit there. A rejection could be a blessing in disguise, and the way you handle rejection tells a lot about you as a person. I would encourage people to ask for feedback, and how you take it speaks volumes. We’ve had instances where someone was a no today and we hired them 6 months later, and that follows you. I interviewed someone 4-5 years ago for a role as an intern at my previous job, didn’t work out, but when I opened our Toronto office she reached out and asked how she could work with me, and because we had that relationship from years earlier she had given a great impression of herself so I was able to bring her into a completely different moment. So your life isn’t over when you get rejected, there’s always another opportunity waiting!

Stergioss: At Shopify we have a similar process. The interviewers get together the same day so everything is fresh. We provide a ranking with notes on thumbs up or down on some values, and we discuss the candidate over the period of an hour or so. Even if it’s a slam dunk we still go through the process to make sure we can see where the candidate will fit in the team and why. Usually, if you’ve gotten to that process in the last interview, the likelihood of doing well is high. In cases where it’s not, we suggest here is what you need to do to improve your coding or thinking, and come back in 6 months or a year for us to reevaluate. Then we may just vet on the things that were the gaps and we can quickly close on next steps.

Karney: At Wealthsimple we debrief the same day, typically the people in the interview and the phone screener. We use a scorecard and generally, there are 4 rankings: yes, strong yes, no, strong no. We do a discussion to elaborate on some things, sometimes we flip votes from a weak no to yes, and we don’t leave the room until we have a decision. And then HR will communicate with the candidate. Some ask for feedback, depending on the situation we’ll give it to them but it’s not generally the case.

Ash: Generally to keep in mind is there is a bias to note; it’s always risky bringing someone new into a company, it’s a huge investment, so sometimes if there’s not consensus or the right position isn’t exactly there, there’s a bias to no because it’s the least risky option.

Nahim: in general you need to accept that you will get rejected. It’s something that happens and sometimes has nothing to do with you and everything to do with the company’s circumstances, maybe they killed the project they were looking to hire for. Be prepared for it and don’t get too emotionally caught up in it. The opportunity may not come in what you think it is, and it may be in the form of what you didn’t expect, but when you get that job it could really propel your career.

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