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Ask HN: What's the most interesting technical screening you've encountered?

9 points by vvoruganti ↗ HN
There's always a bunch of discourse around the right ways to screen candidates for technical abilities. Arguments around if algorithm challenges (LeetCode, Hackerrank) or whiteboarding accurately judge people's abilities. Often I see questions around if the challenge really reflects the day to day job well, and if they are game-able with books like cracking the coding interview gaining popularity

I've also heard horror stories with take home projects that require multiple days of work, generally unpaid, and in the least charitable scenarios feel exploitative and like the company is just getting free labor.

So I was wondering what are alternatives that actually work? Some interesting examples I've encountered over the years include:

- Praetorian's Tech Challenges - https://www.praetorian.com/challenges/

- Fly.io's Gossip Glomers - https://fly.io/dist-sys/

11 comments

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francisofascii
Role play: you pretend it is your first day at the company. The two interviewers take turns acting out different people at the company. You have to pretend to call different people at the company to diagnose a problem. The various characters offer different clues to the issue.
vvoruganti
Was it a live roleplay with other people or a simulated experience via some kind of web app?
francisofascii
Interviewee with two interviewers in a meeting room. No tech involved.
solardev
I love this! It's like a murder mystery over HTTP.
yao420
CTF style challenges like praetorian are the standard for offensive security roles. They are a fun time and really let the teams understand how you approach things.

Only bad experience with that was patreons ctf, the containers didn’t work so I spent the hour interview trying to get it to run. Horrible experience.

vvoruganti
Yeah like the CTF style questions a lot, and would love to see something similar for the more "creative/production" based jobs.

Don't think it would be very appropriate to give someone who's job it is to develop novel/new stuff a challenge like that, but at the same time there are parallels.

Often development jobs have you need to read unfamiliar code that can be poorly documented and then have to either fix or integrate something new into a system. Would love to see something to assess's a candidates ability there.

id00
Never liked LeetCode style questions, so for frontend screening interview, I used to ask to write a tic-tac-toe game with no networking (eg. both players use the same mouse). It's usually provided enough signal in 30-45min to make a decision to pass candidate to the next stage or not
vvoruganti
Nice! That's a pretty well scoped and small enough scale with enough complexity project. My only thing is there is a human in the loop. I think with a competent interviewer they can usually assess the candidate well even if the task isn't that great, but often I see the leetcode style stuff sent as a take home with no human there.

On one hand I get it, there are just so many candidates to have to filter through, but agree don't think it does the best job.

muzani
My favorite was interviewing with Ludeon (known for Rimworld). It was about 1-2 hours long. We whiteboarded on Google Docs, which kinda sucked, but it's not as bad as an actual whiteboard. I flopped the test badly, but it was a great learning experience.

Start with icebreaker questions, what kind of games do you like and why? Go into slightly harder questions - a common request is adding seeds to plants in Rimworld, yes or no?

Then go into the hard technical question - how would you know which part on the screen the caravan should stop at? How would you determine where civilization is on a map? The smart answer is akin to a Monte Carlo simulation, first time I learned of it. Just throw darts (aka sample random points) on the map, give it some civilization rating, then triangulate from there. There's a further optimization where you can search around doors.

It's great because these questions are directly related to the work itself, and you can make a good judgement of someone's abilities in a few hours without needing several sessions of interviews.

For something like banking, I'd ask 1) How do you send a PIN securely from an app? 2) Ok, but how do you do biometrics when the API requires a PIN login? 3) Now let's say we allow users to KYC from an app. How do you detect that someone isn't AI generating their images? You can force users to only send images taken through the app, but an attacker will be able to spoof the app and directly send their image to the API bypassing the app.

drdrey
For a compiler role at Apple, was given an assembly printout and asked “what does this do?”