Roblox Interview Questions — Page 8

Roblox·Software Engineer·Technical Phone Screen

Jun 2026

Roblox software engineer round that jumped straight into coding after a quick self-intro. The question was a rate limiter plus a follow-up, which was familiar territory from prep.

Design a rate limiter. Follow-up questions included.

“Knew this one from prep so I wasn't scrambling.”

View Post

Roblox·Software Engineer·Technical Phone Screen

Jun 2026

This was a follow-up system design round at Roblox, building on an earlier question about rate limiting. The interviewer pushed into more complex territory by introducing multi-field requests.

Given a request that contains multiple fields, how would you design a rate limiter that enforces separate limits for each field independently?

“This was a part two, so I thought I had some momentum.”

View Post

Roblox·Data Scientist·Online Assessment (OA)

Jun 2026

Roblox data scientist OA, 90 minutes, Pandas pipeline work with a situational judgment component thrown in. The time pressure was real and the ethical wrinkles made it more stressful than a pure coding test.

You're 70 minutes into a 90-minute OA. Your Pandas pipeline passes visible tests but fails a hidden one. A teammate offers an unverified fix. You also have a mandatory post-OA survey to complete before the deadline. Which action is best and which is worst, and why?

“The sneaky part isn't the pipeline debugging, it's the survey deadline buried in there.”

View Post

Roblox·Software Engineer·Onsite - System Design / Architecture

Jun 2026

System design round at Roblox focused entirely on building a distributed rate limiter for an API gateway. Pretty deep dive, went well over an hour covering algorithms, scaling strategies, failure modes, and observability. Not a question I'd call easy to wing.

Design a distributed rate limiter for an API gateway, covering per-user, per-IP, and per-API-key limits with support for multiple rules simultaneously.
How would you scale the rate limiter across many gateway nodes? Walk through centralized Redis counters versus local counters with periodic sync, and the consistency vs accuracy trade-offs involved.
What should the system do if the rate limiting store (e.g. Redis) goes down? Fail-open or fail-closed, and why?
How would you handle burst traffic in your rate limiter design?
How would you add observability to this rate limiter? What metrics and alerts matter?
Follow-up: how would you support tiered rate limits, where different users or API keys get different quotas based on their subscription tier?

“I started with functional requirements which felt right, but I spent too long enumerating rule types before getting to the actual design.”

View Post

Roblox·Software Engineer·Onsite - Behavioral / Leadership

Jun 2026

Behavioral onsite at Roblox for a software engineering role. Pretty standard loop covering the usual suspects: past projects, how you handle conflict, ambiguity, cross-functional work, and the classic strengths/weaknesses round.

Walk me through a past project you're proud of. What was your role and what was the outcome?
Tell me about a time you had a conflict with a teammate or stakeholder. How did you handle it?
Describe a situation where you had to work through significant ambiguity. How did you move forward?
How do you work with cross-functional partners like product managers or designers? Give me a specific example.
What motivates you in your work, and how do you stay engaged on projects that aren't exciting?
What are your biggest strengths and weaknesses as an engineer?

“Went fine but I rambled a bit trying to cover too much context upfront.”

View Post

Roblox·Software Engineer·Onsite - System Design / Architecture

Jun 2026

System design round at Roblox for a software engineer role, focused entirely on building an audio detection pipeline for static files. It was a deep, multi-part question that covered basically every layer of the stack, from ingestion to manual review workflows. Dense interview.

Design an audio detection system that processes static audio files, covering functional and non-functional requirements, data model, architecture, and the full processing flow from ingestion to result output.
How would newly uploaded audio files be discovered and queued for processing? Walk through the tradeoffs between a cron/batch approach versus an event-driven model.
How would you classify audio file outcomes into categories like clean, problematic, or needs human review, and how would you design the manual review workflow including assignment, labeling, consensus, requeueing, and audit trails?
How would you approach scalability, throughput and latency targets, fault tolerance, and cost controls for this system?
What success metrics and monitoring or alerting would you define to track both product quality and system health for this audio detection pipeline?

“This was the whole interview basically.”

View Post

Roblox·Software Engineer·Technical Phone Screen

Jun 2026

Roblox technical phone screen with a trie-based autocomplete design problem. Pretty classic LC-adjacent stuff but the follow-up on trade-offs had some teeth to it.

Given parallel arrays of query strings and their timestamps, plus a list of prefix strings, design a data structure that returns matching queries for each prefix ordered by frequency descending and then by earliest timestamp. Walk through preprocessing time, query time, and memory trade-offs.

“I went straight to a trie and started coding before I'd thought through what to store at each node.”

View Post

Roblox·Software Engineer·Technical Phone Screen

Jun 2026

Roblox technical phone screen for a software engineer role. One meaty algorithmic problem that mixed simulation with a bounded-path analysis twist. The problem felt like two questions stapled together and I definitely underestimated the second half.

You have a 2D grid with blocked cells and a robot starting at (0,0) facing north. It runs a command string with move, turn, and repeat-digit instructions. After one full run, report the final position and heading. Then determine if the robot's path stays within some finite bounding square when the instruction string repeats infinitely. Design an efficient algorithm and analyze complexity.

“The simulation part I handled okay.”

View Post

Roblox·Software Engineer·Onsite - System Design / Architecture

Jun 2026

Roblox system design round focused entirely on building a social recommendation feed, the kind where you see what your friends are playing or liking. Pretty deep dive, covered a lot of ground in one question.

Design a social recommendation system that surfaces activity from a user's friends, such as games they played or content they liked. Walk through the data model, how you fan out activity events to followers, ranking, caching, and privacy rules.

“This one is deceptively wide.”

View Post

Roblox·Data Scientist·Technical Phone Screen

Jun 2026

Roblox DS interview with a meaty causal inference question dressed up as a product metrics problem. No fluff, they went straight into the weeds on observational analysis.

Roblox wants to know if players genuinely prefer games made by local creators. Define the primary and secondary metrics you'd use to measure this preference, and since a clean A/B test isn't feasible here, walk through an analysis plan that can credibly estimate the causal effect without just picking up selection bias.

“This one had layers.”

View Post