pcloadletter

Coding interviews are effective

Coding interviews are controversial. It can be unpleasant to code in front of someone else, knowing you're being judged. And who likes failing? Especially when it feels like you failed intellectually.

But, coding interviews are effective.

One big criticism of coding interviews is that they end up filtering out a lot of great candidates. It's true: plenty of great developers don't do well in coding interviews. Maybe they don't perform well under pressure. Or perhaps they don't have time (or desire) to cram leetcode.

So if this is happening, then how can coding interviews be effective?

Minimizing risk #

Coding interviews are optimized towards minimizing risk and hiring a bad candidate is far worse than not hiring a good candidate. In other words, the hiring process is geared towards minimizing false positives, not false negatives.

The truth is, there are typically a bunch of good candidates that apply for a job. There are also not-so-great candidates. As long as a company hires one of the good ones, they don't really care if they lose all the rest of the good ones. They just need to make sure they don't hire one of the no-so-great ones.

Coding interviews are a decent way to screen out the false positives. Watching someone solve coding challenges gives you some assurance that they can, well, code.

Why I myself like coding interviews #

Beyond why coding interviews are beneficial for the company, I actually enjoy them as an interviewer. It's not that I like making people uncomfortable or judging them (I don't), but rather I like seeing how potential future colleagues think. How do they think about problems? Do they plan their solution or just jump in?

This is a person with whom I'll be working closely. How do they respond to their code being scrutinized? Do I feel comfortable having to "own" their code?

On automated online assessments (OAs) #

The junior developer market right now is extremely competitive and therefore it is common to use automated coding challenges (OAs) as an initial screen.

OAs kind of accomplish the false positive filtering mentioned above, but that assumes candidates aren't cheating. But some are. So you're filtering your candidate pool down to good candidates and dishonest candidates. Maybe that's worth it?

Additionally, OAs don't give you any chance to interact with candidates. So you get no sense of what they'd really be like to work with.

All in all, I'm not a fan of OAs.

Far from perfect #

Coding interviews are far from perfect. They're a terrible simulation of actual working conditions. They favor individuals who have time to do the prep work (e.g., grind leetcode). They're subject to myriad biases of the interviewer. But there's a reason companies still use them: they're effective in minimizing hiring risk for the company. And to them, that's the ball game.