Roblox Software Engineer Interview Questions
Roblox Software Engineer interview questions tend to reflect the company’s focus on real-time, highly concurrent experiences and a creator-driven product model. Expect evaluations of core computer science fundamentals—algorithms, data structures, complexity reasoning—alongside systems thinking for scalability, networking, latency, and reliability. Interviewers also assess code clarity, tradeoff reasoning, product sense, and collaborative ownership; demonstrating how you designed, measured, and iterated on real systems will make answers more compelling. In practice you’ll typically see a recruiter screen, one or more timed coding rounds that probe algorithmic problem solving, a system-design or architecture discussion focused on large-scale and real-time constraints, and behavioral interviews that explore teamwork and impact. For interview preparation, prioritize timed coding practice, study design patterns for distributed real-time systems, and review platform-specific concepts (concurrency, event-driven architectures, and common performance pitfalls). Bring concise STAR stories anchored to measurable outcomes and be ready to discuss tradeoffs and instrumentation choices for systems you’ve built.
Design a scheduled payment system
System Design: Scheduled Payment Service Context You are designing a backend service that allows end users to: - Schedule a payment for a future date/...
Find most frequent call stack from logs
Given an array of log entries for a single-threaded program's function calls, each entry is either '->Name' (function entry) or '<-Name' (function exi...
Design real-time game matchmaking service
Design a Real-Time Game Matchmaking Service Context You are designing the matchmaking subsystem for an online multiplayer game that supports multiple ...
Design a real-time favorites service at scale
Design: Real-Time Favorites/Unfavorites Service at High Scale Context Design a backend service that lets users favorite/unfavorite items (e.g., posts,...
Design game matchmaking and waiting queue
Design a scalable game matchmaking and waiting-queue system Context You are designing the matchmaking system for a large real-time multiplayer game. P...
Implement queue-based rate limiter with multi-key limits
Implement a rate limiter with method allow(timestamp) that returns true if a request is allowed under a limit of K requests per rolling window W milli...
Design resource loader and ROS-like pub/sub
System Design: Resource Loader and ROS-like Publish/Subscribe Context You are designing two foundational systems for a large-scale, real-time interact...
Design the manual review workflow
System Design: Human-in-the-Loop Review Subsystem Context You are designing a human-in-the-loop (HITL) review subsystem for a large-scale safety platf...
Design a static audio detection system
System Design: Static Audio Issue Detection Pipeline Design a production-ready system that detects policy issues in user-uploaded, static audio files ...
Handle feedback, conflict, missed metrics
Behavioral & Leadership Interview: Feedback, Conflict, and Missed Metrics Context: In a Software Engineer onsite behavioral round, answer the followin...
Design a Static Audio Detection System
System Design: Static Audio Detection Pipeline Context Design an offline (non-live) audio detection system that processes static audio files (e.g., us...
Detect runs and collapse a numeric grid
You are given an m x n grid of digits (0– 9). Phase 1: Find every horizontal or vertical run of length ≥ 3 consisting of the same digit. For each run,...
Simulate robot path and detect boundedness
A robot starts at (0, 0) facing north on an infinite 2D plane. It executes a command string s consisting of 'G' (move forward one unit), 'L' (turn lef...
Design sliding-window rate limiter with multi-keys
Design a Precise Sliding-Window Rate Limiter Context You are designing a rate limiter for an API that must enforce a true sliding-window limit (i.e., ...
Find largest digit-sum bucket size
You are given two integers low and high (inclusive). Define s(x) as the sum of the decimal digits of x. For every integer x in [low, high], place x in...
Rank queries by prefix, frequency, and time
You are given three arrays of the same length n: - queries[i]: a non-empty string representing the text of the i-th query. - timestamps[i]: an integer...
Detect robot state after movements
Question Implement an algorithm to determine whether a robot following a given set of movement instructions ends in a valid recognized state (variant ...
Handle feedback, conflict, and missed metrics
Behavioral & Leadership Prompts (Software Engineer Onsite) 1) Giving Critical Feedback Describe a time you gave someone critical feedback: - What was ...
Outline the ML inference and labeling pipeline
Audio Detection System: ML Inference and Data Pipeline (Model Architecture Out of Scope) Context and Assumptions Design the machine learning inference...
Define success metrics and monitoring
Design success metrics, evaluation, and monitoring for an audio detection system Context You are defining the measurement, evaluation, and rollout pla...