Of course, lots of people are employed despite giant holes in their knowledge of CS fundamentals. There’s more to being an effective developer than having good fundamentals. A lot more.
But there’s still a lot of very important concepts in CS that people should learn. Concepts like performance engineering, security analysis, reliability, data structures and algorithms. And enough knowledge of how the layers below your program works that you can understand how your program runs and write code which lives in harmony with the system.
This knowledge is way more useful than a lot of people claim. Especially in an era of chatgpt.
If you’re weak on this stuff, you can easily be a liability to your team. If your whole team is weak on this stuff, you’ll collectively write terrible software.
Alternatively, whiteboard coding exercises are a hazing mechanism to weed out candidates who have certain forms of anxiety or can't perform well under extreme scrutiny and time pressure. Which could be valid selection criteria for certain jobs. But let's be honest and admit that whiteboard coding exercises aren't actually a proxy for anything else, or at least we have no scientific evidence on that point.
First, whiteboard interviews were a great selection criteria for about 30 seconds before it became public knowledge that being able to pass them was a ticket to a google salary. Subsequently, they functioned literally at all while under the pressure of literal billions of people knowing that they were the ticket to a google salary. A criteria surviving this second challenge is extremely impressive.
To put it another way: I can hire based on open source contributions instead of credentials and interview performance. If google decided tomorrow to start hiring based on open source contributions, then their new criteria would leak on monday, and on tuesday the pull requests queues of every major project would simultaneously splatter like bugs on windshields.
> But let's be honest and admit that whiteboard coding exercises aren't actually a proxy for anything else, or at least we have no scientific evidence on that point.
Nah. Whiteboard interviews test a bunch of traits that are important in a job. They aren't designed to be a baroque hazing ritual.
More generally, we could make a list of desirable / necessary qualities in a good hire based on what they'll spend their time doing. Imagine you're hiring someone to work in a team writing a web app. Their job will involve writing javascript & CSS in a large project. So they need to write code, and read and debug code written by their coworkers. They will need to present their work regularly. And attend meetings. The resulting website needs to be fast, easy to use and reliable.
From that, we can brainstorm a list of skills a good applicant should have:
- Communication skills. (Meetings, easy to work with, can explain & discuss ideas with coworkers, etc).
- Understanding of performance, UX concepts, software reliability, etc
- Knowledge of how web browsers work
- Capacity to learn & solve unexpected problems
And so on.
Now, an idealised interview process would assess a candidate on each of these qualities. Then rank candidates using some weighted score across all areas based on how important those qualities are. But that would take an insane amount of time. The ideal assessment would assess all of this stuff efficiently. So you want to somehow use a small number of tasks to assess everything on that big list.
Ideally, that's what whiteboard interviews are trying to do. They assess - all at once - problems solving skills, capacity for learning, communication skills and ideally CS fundamentals. Thats pretty good as far as single task interviews go!
> we have no scientific evidence
There's a mountain of evidence. Almost all of it proprietary, and kept under lock and key by various large companies. The data I've seen shows success at whiteboard interviews is a positive signal in a candidate. Skill at whiteboard interviews is positively correlated with skill in other areas - but its not a perfect correlation. Really, the problem really isn't whiteboard interviews. Its that people think whiteboard interviews give you enough signal. They don't. They don't tell you how good someone is at programming or debugging. A good interview for a software engineer must assess technical skills as well.
Speaking as someone who's interviewed hundreds of candidates, yes. There are some people who will bomb a whiteboard interview but do well at other technical challenges you give them. But they are nowhere near as common as people on HN like to claim. Most people who are bad at whiteboard interviews are also bad at programming, and I wouldn't hire them anyway.
The reality is, most people who make homebrew get hired. There's plenty of work in our industry for people who have a track record of doing great work. Stop blaming the process.
