The Ultimate Guide to Competency-Based Interviews as a Software Engineer

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No matter how good your coding interview skills are, most companies will ask you competency-based questions during your interview or schedule at least one session dedicated to it.

I have been interviewing with various companies like Google, Amazon, Goldman Sachs and Bloomberg over the past few months and have compiled all of the questions that they asked and lessons that I’ve learned from them.

Disclaimer: I am writing about my own experience as a software engineer in the UK with 2 years of experience, applying for relevant roles based in the UK.

Typical Interviewing Process

1. Submit an application form or contact through LinkedIn
2. First call with HR
3. Phone interview
4. Final (sometimes virtual) onsite interviews

I have seen different variations of how different companies conduct their competency/behavioural interviews. So I will be discussing where they could take place at different stages of the process.

First call with HR (15–30 minutes)

Usually, this is used as a sanity check to put a voice to a CV/application or if they reached out to you on LinkedIn, to match you with a team that could be a potential fit for you.

They will typically ask basic questions that you might think are repeated from your CV or application form. Again, these are sanity checks to verify your background and to get a better understanding of your current position. They would usually ask basic questions like:

• Your background
• Programming languages and tech stacks that you’re using or familiar with
• Your current role
• Location preference (if they have offices around the world)
• Are you interviewing with other companies? If so, do you have any deadlines?
• Current salary and salary expectations

However, don’t be shocked if they randomly throw simple competency-based questions like:

• Why do you want to work at our company?
• Why do you want to leave your current role?
• What interested you about the role that you’re applying for?

Some companies like Google might ask you some technical questions (e.g. what data structure would you use for priority queues?), but they won’t criticise you heavily on this as they are calling from HR and to give you a taste of what the technical interviews could be like.

At the end of the call, they would usually tell you the next steps and when they’d get back to you to proceed with your application.

Phone interview (30–60 minutes)

Depending on the company, they might do a technical (coding) interview for this phone call or for a few, a competency-based interview.

At this stage, it would usually take around 30 to 60 minutes and will be conducted by an engineer who might or might not be working in your future team. Most companies would do this round through a phone call and not a video call. So take this opportunity to have your notes on hand to be able to quickly refer to. I will talk about how to write useful notes later on in this article.

For this round, research about what the company does, its principles and prepare some stories where you showed your relevant skills and demonstrated times when you went above and beyond.

Tips on how to answer company-related questions:

• Research about the company’s values and principles (e.g. Amazon has their Amazon Leadership Principles). This can be found on their Careers page on their website.
• Relate these principles to how you’ve done your work in the past.

Final interviews (at least a whole day)

So you’ve made it to the final interviews. Well done! Pat yourself in the back and push yourself once more because this isn’t going to be any easier.

From what I’ve experienced, the final interviews can vary from a whole day (consisting of 4–5 interviews with breaks in between) or spread out into multiple days (some companies might split them across 2 days; technical interviews on day one and competency-based interviews on day two).

Some companies (like Amazon) would even ask competency-based questions on each interview round after the technical interview section.

Thankfully, all the practice and preparations that you’ve done thus far won’t go to waste, since the competency-based questions would be in a similar format but in a more in-depth manner.

At this stage, the interviewers are trying to assess:

• Your motivation for applying to the company.
• If you (and your working style) would be a good fit for the team.
• Your expectations and what you’re looking to get out of this role (remember that interviews are a two-way street! Your expectations need to align with what the team can provide).

These interviews will be conducted by members of the team and managers or team leads of the organisation or department.

This is the perfect opportunity for you to ask questions specific to the team, for example:

• What the role looks like on a day-to-day basis.
• If they have any ongoing or upcoming projects and the details (you can then evaluate if this sounds interesting to you).
• What the work-life balance looks like in the team.
• If they allow flexible working (remote locations, flexible working hours, etc.).

A guided template on preparing for your competency-based interviews

Make sure you have some stories prepared to share in your interviews. Most stories are interchangeable and you can frame it in a different perspective. For example, for a project where you made a mistake and fixed it, this could fit into questions like ‘tell me about a time when you made a mistake’ and ‘tell me about a time when you went beyond your way to improving something’.

Most asked questions:

• Tell me about yourself.
• What are you looking for in your next role?
• Why do you want to work for our company? You can comment about their tech or leadership culture, the prestige of the company and how you’d like to work alongside intelligent people within the firm.
• Why do you want to leave your current role?
• Talk me through one of the projects that you’re proudest of.
• What is the most (technically) challenging task that you’ve encountered?

Commonly asked questions:

• Tell me about a time when you did more than what was expected.
• Tell me about a time when you received harsh feedback.
• Tell me about a time when you had to deliver results within a tight deadline.
• Tell me about a time when you had a conflict or a disagreement with a teammate.
• How do you gather requirements? (SDLC-related questions)

Template for creating your list of stories

The first few times I had my competency-based interviews, I struggled to recollect my experiences and stories at work and formulate my thoughts on the spot, whilst trying not to miss out the important points I wanted to convey.

I’m quite a visual person so drawing up tables for my list of projects help me organise my thoughts in advance and to help me remember my stories better.

I created 2 templates that I found useful whilst practising.

• First one is an exhaustive list of your projects or scenarios that you’ve been in and then creating the flow of each story; background, task and actions, results and what I learned from that experience.
• The second one is categorising each experience on a matrix based on its attributes.

First template: an exhaustive list of projects you’ve worked on and the process/outcome of each

Use this guide to list down the flow for each project/task.

Remember to demonstrate how these experiences make you a great candidate for the firm, how your values align with theirs and how you are always willing to improve and keep developing your skills over time.

Second template: come up with potential questions that they might ask based on their values and principles

List down the list of characters or qualities that the company values and 2 ‘positive’ and ‘negative’ columns, indicating good or bad traits. Write them down in the corresponding cell. Then, for each scenario, write down a story or experience that is relevant to that. The stories might overlap, but that’s okay!

Again, for all the negative experiences, don’t forget to mention what you’ve learned from them and what you’d done differently from that point.

Once you’ve written up your table of stories and memorised them, keep them near you (if you’re doing a virtual interview, this would be handy to briefly glance over and hopefully will help trigger the stories from each project).

Tips on practising:

• Write down a comprehensive list of projects that you’ve worked on and choose the ones where you’ve had a major role in it.
• For each of them, write a full story using the STAR method.
• Rehearse telling your stories out loud (I’ve found that having a friend to do mock interviews with you helps a lot! At least for me, the thoughts that I have in mind doesn’t translate well when being spoken aloud)
• Once you’ve memorised your lines, underline the keywords that will help trigger your memory and then condense each point into 3–4 words on a written or digital note.
• If you are having a virtual interview, split your screen to the video call window and your condensed notes (preferably within a single page). This will provide you with some hints and triggers that will allow you to recall your stories during your interview. Just remember to be aware of your eye movements and make sure that you don’t look like you’re reading off the screen.