On technical phone screens

There is an ugly truth about technical phone screens: they don’t work that well for either the candidate or the company.

Phone screens don’t work well for candidates because they can often be a coin-toss, where chance plays as much of a role as experience or skill. They don’t work well for employers because a better way to do early screening doesn’t exist, yet the majority of candidates still get rejected on-site.

Many guides talk about algorithms, data structures, and system design questions you should study. I agree, but this has been covered better by others. Instead of that, I want to talk about logistics and your presentation as an engineer.

These tips are written based on my experience as both an interviewer and interviewee at major software companies.

Organization and equipment

To give yourself the best chance for your skills to shine, make sure you plan for the call, and that your equipment won’t get in the way.

Block off the time, along with some padding on either side. If you are currently employed, make it clear that you need personal time off: don’t hope to sneak away for an hour without interruptions. If you aren’t currently employed, take the interview time into account and don’t schedule any personal obligations immediately before or after the interview.

Have an appropriate environment to take the interview. Public spaces are right out: you should find a quiet room to yourself with little background noise. If you live with others, let them know you’ll need some quiet time. Silence your alarms, and turn off the Roomba.

You’ll likely be taking the call on a cellphone since fixed phone lines are rare in 2020. Make sure you have good reception in the room where you’ll be taking the call. Connect your phone to a charger. Don’t rely on using the speakerphone, instead use a headset. If you opt for a wireless headset, make sure it’s charged and can last through an extended phone call.

Unexpected things, reschedules and cancellations

Any plan you make can go awry. What separates professionals from the rest is the ability to handle these things with grace and courtesy.

If you have a personal reason that makes it impossible for you to take the interview at the prearranged time, inform the employer as soon as possible. A good company will understand the need to reschedule.

It’s also possible that the interviewer will be suddenly unavailable or unable to reach you. If you don’t get a call by about 10 minutes past the arranged time, e-mail your recruiter: they might not be aware that anything is wrong.

Should you decide to withdraw from the interviewing process (for example, if you received an offer from a different employer), inform the recruiter without delay.

Some companies will refuse to reschedule your call if you ask for it. This is a negative signal about the employer.

Talking about your experience

A written resume covers the essentials of your work and educational experience. Its purpose is to summarize and inform. Talking about your experience is a different beast altogether.

Despite the common belief that a good resume is crucial, the reality is more complicated. At least some of the interviewers don’t read a candidate’s resume at all, instead preferring to have the candidate speak for themselves. Most of the interviewers I worked with won’t pay more than minimal attention to your education credentials.

Two things are essential: the exact work you did for previous employers (or college courses), and how that work impacted the employer and yourself.

The description of your work should be technical. Discuss the technologies you used, how they fit the solution, and the difficulties you encountered along the way. If the interviewer isn’t familiar with a tool you used, be prepared to give a high-level overview. If the interviewer is particularly interested, dive deeper into your work.

Best candidates have previous work or education experience that impacted their employers or themselves. How does the experience you are talking about fit those categories? Did you reduce the cost of some process, increase the performance, or enable a new use case? How did you change during this project? Did you come face to face with a personal failing, or did you learn something new about yourself?

The idea isn’t really to impress your interviewer. Instead, think of it as discussing your experiences and trying to find shared professional values.

My ideal candidate is a person who thinks about their work and follows up their thoughts with action to final delivery.


Programming during on-site interviews and technical screening interviews is a divisive point for candidates and interviewers. It’s not clear how this skill relates to being a good fit for a software engineering position.

What is true is that it is a different skill altogether than actual software engineering. On the other hand, it shows that you speak a common language of well-known data structures, algorithms, and methodologies for using them. This shared language of basic ideas is useful in a world where people you work with may not be on the same continent, much less in the same room as you.

It’s unlikely that this interviewing type will go out of style anytime soon. Your best bet is to accept that this is a skill that you may need to learn and simply do so.

You should know about two things that all interviewers experience: we can’t hear your thoughts, but we can (mostly) hear you typing.

Because we can’t hear your thoughts, your goal should be to verbalize as much of your thought process as possible. Repeat the question out loud. State aloud any assumption you make about the solutions. Talk about the tradeoff between a simple and optimal solution. Keep your mouth running at all costs.

Interviewers can, however, hear you typing. And if you are typing, there should be code showing up in the shared editor you are using. If it’s not, something strange is likely happening. You may be writing a set of notes in a separate document or sketching out a solution. But the interviewer can’t tell. If they are direct, they may ask you about where the typing is going to. If they aren’t outspoken, you may end up with a rejection.

Parting points

Guides can teach you how to answer algorithm questions, and how smiling or standing up during a phone call communicates energy to your interviewer.

Those articles cannot teach you that hiring is about finding people who are a cultural and professional fit for the employer. While a bit of pride isn’t misplaced, remember that employers likely have many more candidates waiting, none of us are irreplaceable, and most of us don’t have any truly unique skills.

Technical interviewing is a precarious journey. Sometimes the fates will align, and you’ll wash out despite your qualifications.

When, not if, that happens, remember: there is something to be said about second attempts, and being as gracious when succeeding, as you are when failing.

Good luck!

These writings represent my opinions and are not related to my employers.
Licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.