Technical Interviews aren't merely technical

July 17, 2019

After having conducted over a hundred technical interviews for software engineering hires, I’ve come to realize that there are many elements that contribute to making a great interview experience that are not technical at all.

A coding interview at a typical FAANG involves coming up with an algorithm to solve a problem (usually on a whiteboard or laptop) in a short amount of time (around 45 minutes). The candidate will go through a few of these (and some other non-coding interviews) before a hiring committee makes a hiring decision based on feedback from the interviewers. It’s not a perfect process. Great candidates can certainly have bad days and do poorly.

This post isn’t a proposal about how to improve the process, but some thoughts on how to let the candidate have the best experience possible in the present setup:

1. Put the candidate at ease first.

It can be really stressful to have your career direction determined over the course of several 45 minute interviews! It’s not surprising that some candidates are nervous during the process.

The last thing you want to do is dive right into a deep technical discussion. Ask the candidate how their day has been going first. Let them know that you’re there to work together on a problem with them, and it’s not so much about you asking a question and them providing a response. It’s also good to let candidates know that a whiteboard interview is an artificial situation, and that they aren’t expected to be perfect. Don’t be nitpicky about tiny syntax errors or the exact order of arguments to a substring call.

One of the best interviews that I had when I was interviewing for a job after college hardly felt like an interview. It felt like a casual and friendly conversation (while actually covering technical material quite smoothly). I’ve tried to recreate that experience for candidates that I’ve interviewed since.

2. Come well prepared.

Interviews where you don’t get a sufficient signal about the candidate’s ability are a waste of everybody’s time. Come prepared with more questions than you’d expect to ask. Also, make sure that you’ve thought about every corner case in your problems and potential directions that candidates could take.

Your job as an interviewer is to steer the candidate to a working solution without too much hand-holding. After a few interviews you should have a reasonable idea about where candidates typically stumble, and you should be prepared to step in and help them out.

Every once in a while you will get a candidate that doesn’t need any help whatsoever. However, a majority will need some sort of assistance with the problems you present before them. The key to a smooth interview process is to never let the candidate feel stuck or helpless. A well timed hint can go a long way in helping candidates make progress even when the problem they are solving is beyond them.

I like to pick problems that can be scaled up in difficulty depending on how much progress the candidate makes. I try to structure them such that most candidates can solve at least parts of them, and it gives me the option to work through the whole thing with more skilled candidates.

3. Focus on the candidate, not your questions.

Ask the candidate what their areas of strength are. Do some research on their past work. Don’t grill candidates about front-end performance if they’ve only done back-end distributed systems in the past. Tailor your questions on the fly to something that will tease out the candidate’s problem solving ability more accurately.

The interview is about the candidate and their ability. This is a big day for them. Your questions are merely tools to facilitate a discussion. You may meet candidates that struggle with your problem initially but demonstrate great perseverance and come up with a working solution eventually.

You’re trying to evaluate if this person is someone that you would like to work with, not if they aced your test. The interview should not feel like a test.

4. Pace the interview well.

An interview that flows well will feel good for both the interviewer and the candidate. Time management is paramount.

Make sure that you keep track of time in five or ten minute slots. You want to avoid awkward silences and long periods where the candidate is just staring blankly at the whiteboard.

If the candidate is not making any progress at all and you need to give up on a particular problem, do so elegantly without making them feel like they messed up. Point them in the general direction that you were expecting them to take and then move on to another problem.

Also make sure to budget some time at the end of the interview to discuss other things and wind down. The last thing you want is the next interviewer knocking on the door while the candidate is furiously struggling to get their solution working.

5. Help candidates take home something positive.

I firmly believe that every candidate must get something out of the interview, even if they don’t get the job. While you may not be allowed to give the candidate direct feedback about their performance on the interview, you can give them several other insights.

Talk about your role at the company and how you got there. Candidates that are not ready to be hired may learn something that they were missing.

Give the candidate some perspective about roles that you think are a good fit for their interests and skillset. For example, if the candidate likes machine learning, talk about what typical machine learning folks do at your company. Even if they don’t end up getting hired, you may help them narrow down their search for the next place that they interview at.

Overall, remember that this is a real person that you are talking to, not a resource that could potentially ease the workload of your team. Thank them for their time and hope that they find success in their careers (even if that is elsewhere).

Views expressed are my own and not my employer’s.

Nicolo John Davis
Nicolo Davis