Roblox Interview Questions
Practice the exact questions companies are asking right now.
Find maximum follow depth using recursion
You are given a directed follows relationship representing a social graph: - Each record (follower_id, followee_id) means follower_id follows followee...
Optimize bread-factory pipeline for max profit
You can assemble a production line by choosing modules of three types: Mixers, Ovens, Packers. Each module i has (type, build_cost_i, throughput_i uni...
Extend counter to per-client rate limiting
You are extending the recent-requests counter to support per-client rate limiting. Each request now includes a clientId identifying the caller. You mu...
Implement recent-requests counter
You are designing an in-memory component for a web service that needs to track how many requests ("hits") it has received in the last 5 minutes. Imple...
Explain an ML project end-to-end with tradeoffs
Pick one of your production ML projects and walk through it end-to-end. Be specific: 1) Problem framing (prediction vs causal decisioning), target def...
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...
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 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 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...
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...
Demonstrate fit with quantified stories and motivations
Behavioral & Leadership Technical Screen Prompt (Data Scientist) Provide two stories—one professional and one personal—that demonstrate you’re a stron...
Implement robust one/two-sided p-value function
Implement p_value(stat, alternative, dist, df=None) Context: You're building a small, production-quality helper to compute p-values for common one- an...
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 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...
Detect shuffle-mode sequence
Question Given a playlist of distinct songs and two player modes—Random (each next song chosen independently and uniformly at random, with replacement...
Randomly partition array into k segments
Question Given a list of integers and an integer k representing the number of segments, write a function that randomly partitions the list into k non-...
Design in-game payment wallet system
System Design: In‑Game Currency Transfers and Analytics Context You are designing the in‑game currency subsystem for an online game. Players can trans...
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., ...
Implement Python Function for Statistical Test P-Values
Scenario You need a utility that calculates p-values for one-sided and two-sided statistical tests. Question Write a Python function compute_p_value(s...
Determine Player Preference for Local Game Creators
Player Preference for Local Creators — Metrics and Causal Estimation Without A/B Tests Context You are evaluating whether players on Roblox prefer gam...