Roblox Software Engineer Interview Experience — One Technical Screen, a Rare Trie/Heap Question, No Offer

A bit unlucky — I ran into an interviewer for this round. At first I was pretty happy, thinking we might have something in common, but then I got the lowest-frequency, hardest question in the database, and I didn't finish it.

I ended up failing. I'm not sure whether it was because of the coding, or my resume, or maybe just because I didn't finish the coding — either way, my feedback didn't stack up against the other candidates.

I've ground through 1500 LeetCode problems, and I still couldn't crank this one out live.

After the interview I found out someone had posted about this exact question before — the text is below. It's just super low-frequency; I couldn't find the original link anymore:

The second question was similar to LC 642. I spent almost ten minutes discussing the trie structure with the interviewer and ran out of time.

The second question was similar to LC 642: three arrays — queries, timestamps, and prefixes. For each prefix, find its matching query and output them ordered by frequency of occurrence; if there's a tie, break it using the smallest timestamp.

The problem statement was long and the wording was pretty vague, so reading through it and clarifying ate up a good chunk of time, and there was also a lot of code to write. I thought of using a trie to find the prefix and then optimizing with a heap at the end, but I just didn't have enough time — I didn't even finish the first part.

Update (Dec 2, 2025):

Yeah, this kind of thing is inherently pretty uncertain and random, since the screen is only one round. Broad generalizations don't tell you much — even if 99% of interviewers out there are great, I might just be the one who runs into that 1%. It's already full of uncertainty and randomness. I took a shower and I'm back to full strength, haha. In this update, I also wrote that I had run into an interviewer who gave me a fairly difficult, unmodified LeetCode Hard problem and had me run it live on the spot. If you're going to be out here interviewing, you need to accept that objective uncertainty and randomness.