Roblox Interview Questions — Page 2

Roblox·Software Engineer·Technical Phone Screen

Apr 2026

Roblox software engineer interview with a scheduling problem that's pretty classic but still trips you up if you haven't thought through the edge cases recently.

Given a list of meeting time intervals, find the minimum number of conference rooms needed so no two overlapping meetings share a room.

“Classic heap problem but I second-guessed myself on whether to sort by start or end time first.”

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Roblox·Software Engineer·Technical Phone Screen

Apr 2026

Roblox software engineer interview with a pretty gnarly algorithm question about music player modes. The problem felt deceptively clean on the surface but had enough edge cases to keep me on my toes for a while.

You have a playlist of distinct songs and two playback modes: Random (picks next song uniformly at random with replacement) and Shuffle (generates a random permutation and plays through it without repeats, then optionally reshuffles). Given a sequence of n songs recorded from an unknown starting point, design an algorithm to determine whether that sequence is consistent with Shuffle mode. Include time and space complexity analysis and cover edge cases like repeated songs and n=1.

“I actually liked this problem once I got my head around it.”

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Roblox·Software Engineer·Technical Phone Screen

Apr 2026

Roblox technical phone screen that was basically one meaty graph problem the whole time. The question sounds straightforward until you get into the tie-breaking rule and realize you need more than just a standard BFS approach.

Given a list of dependencies as a 2D array of directed edges (e.g. [[a, b], [c, d], ...] meaning a must come before b), return a valid topological ordering. When multiple nodes are available at the same step, break ties by the order each node first appears as a source in the edge list.

“I started with Kahn's algorithm and felt pretty good about it, but the tie-breaking requirement tripped me up for a few minutes.”

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Roblox·Software Engineer·Onsite - System Design / Architecture

Apr 2026

Roblox system design round, and they went straight for a rate limiter. Pretty classic topic but the scope they expected you to cover was wider than I anticipated, multi-tier limits and failure modes included.

Design a rate limiter that enforces a maximum number of requests per identifier (user, API key, or IP) within a given time window.
How would you handle storing and synchronizing rate limit counters in a distributed system, and what problems arise with clock skew or race conditions across nodes?
How should a rate limiter communicate limit status to API clients, including what headers or response codes to use?
If the counter store becomes unavailable, should the rate limiter fail open or fail closed, and what are the tradeoffs?
How would you design rate limits that operate at multiple levels simultaneously, such as per-user, per-tenant, and globally, and how do those limits interact with each other?

“I started with fixed window because it's the easiest to explain, but they immediately pushed on burst handling and I had to pivot to sliding window counter.”

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Roblox·Frontend Engineer·Executive / Final Round

Apr 2026

Final round at Roblox for a Frontend Engineer role, focused almost entirely on behavioral stuff at the executive level. No code, just a lot of questions about how you make decisions and whether you can tell a coherent story about your career. Felt more like a conversation than an interview, which threw me off a little.

Walk me through why you've moved between companies and why you want this role specifically.
Tell me about a project where you identified a problem on your own and made a call nobody asked you to make. What happened?
Tell me about a proactive decision you made that didn't work out. What did you do when it went wrong?
Was there a point in your career where leaving would have been easier but you chose to stay? Why?
In that project decision you described, who pushed back on you and how did you handle it?
If you joined and noticed something clearly broken in your first month that nobody seemed to own, what would you do?

“This is the one I prepared the least for and regretted it.”

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Roblox·Software Engineer·Onsite - System Design / Architecture

Apr 2026

System design round at Roblox for a software engineer role, focused entirely on an audio detection pipeline. No coding, just a deep dive into ML infrastructure and data flow for what felt like a pretty niche domain.

Walk through the ML inference and data pipeline for an audio detection system, excluding model architecture. Cover feature extraction, keyword spotting, and denoising.
How would you score and threshold model outputs for this kind of audio detection system?
How do you calibrate model confidence and deal with class imbalance in this pipeline?
What's the contract for model inputs and outputs, and how do you store transcripts, embeddings, and intermediate artifacts?
How are manual labels generated and fed back into the system for active learning?
How do you detect model drift and manage versioning for both models and thresholds?

“I started with spectrograms and MFCCs which felt safe, but the denoising piece tripped me up a bit.”

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Roblox·Software Engineer·Onsite - System Design / Architecture

Apr 2026

Roblox system design round for a software engineer role. The question was a payment system design with some tricky data modeling requirements around time-series balance tracking. Dense problem, not a lot of fluff.

Design a payment system for an online game that supports in-game currency transfers between accounts. Your design should include data models and APIs for: (1) querying total inflow and outflow for any account over the last 24 hours, and (2) retrieving an hourly balance time series for the past 30 days for any account.

“The first part felt manageable.”

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Roblox·Software Engineer·Onsite - System Design / Architecture

Apr 2026

Roblox system design round for a software engineer role, one big question about building a matchmaking service from scratch. Pretty open-ended, which I wasn't fully ready for.

Design a matchmaking service for an online multiplayer game, covering how players queue up, how matches are formed based on skill and region, and how the system scales globally.

“I started with the data model and probably spent too long there.”

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Roblox·Software Engineer·Technical Phone Screen

Apr 2026

Roblox software engineer phone screen, 45 minutes, two questions. The first was a rate limiter design. Pretty standard session, nothing too surprising.

Design a rate limiter.

“Classic problem, you've probably seen it a dozen times.”

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Roblox·Data Scientist·Technical Phone Screen

Apr 2026

Roblox data scientist interview with a pretty meaty optimization problem that felt more like a systems/algorithms round than anything I expected for a DS role. The question had multiple layers and I wasn't fully prepared for the depth they wanted.

You're building a production line from three module types (Mixers, Ovens, Packers), each with a build cost and throughput. Given a budget, select a combination of modules to maximize hourly profit, where throughput is capped by the bottleneck stage and build costs are amortized per hour. Design an algorithm for this.
What is the time and space complexity of your solution, and can you justify whether it's optimal or just an approximation?
How would you extend the solution if each module has a warmup period that temporarily reduces its throughput for the first T minutes? Think about horizon-based planning or modeling it as a min-cut on a time-expanded network.

“This took me a while to even parse correctly.”

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