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Software Engineer Interview Questions
Practice 9403 coding, system design and machine learning questions from 546 companies, sorted by role, topic and interview round. Every question has step-by-step hints, a code runner that supports 8 languages and an AI mentor; members also get the full solution walkthrough.
- 9403
- Questions
- 546
- Companies
- 11
- Topics
- 8
- Languages
Showing 4711–4740 of 5874 results
- RobinhoodEasySoftware EngineerDesign in-memory payment and friendship system
This question evaluates object-oriented design skills, stateful in-memory data structures, request processing, and correctness constraints such as friend relationships, unique request IDs, and atomic balance transfers.
Coding & AlgorithmsTechnical Screen - RobinhoodHardSoftware EngineerExplain Project Complexity and Scalability in a Deep Dive
Prepare a project deep dive that explains data flow, business invariants, personal ownership, measured bottlenecks, and credible scalability tradeoffs.
Behavioral & LeadershipOnsite - RobinhoodMediumSoftware EngineerExplain auth, key rotation, secrets, and incident response
This question tests your knowledge of secure microservice communication, the lifecycle management of sensitive credentials, and the operational procedures for mitigating security breaches.
Software Engineering FundamentalsOnsiteSecurityMicroservicesAuthentication - RobinhoodMediumSoftware EngineerFlatten Fractional-Share Inventory and Record Trade Logs
Process fractional-share buys and sells with exact hundredth units, whole-share market flattening, dollar-order conversion, and ordered inventory-perspective logs.
Coding & AlgorithmsTechnical Screen - RobinhoodMediumSoftware EngineerGive a Project Deep Dive Grounded in Personal Ownership
Tests your ability to present a deep dive into an impactful software project you led or contributed heavily to, emphasizing architectural trade-offs, personal ownership, failure modes, and measurable outcomes.
Software Engineering FundamentalsOnsiteProject Deep DiveSystem ArchitectureBehavioral - RobinhoodMediumSoftware EngineerGive a Technical Deep Dive into a Software Project
Practice a project deep dive covering architecture, personal ownership, implementation decisions, validation, outcomes, and lessons learned.
Software Engineering FundamentalsOnsite - RobinhoodMediumSoftware EngineerHandle security vs velocity conflicts across teams
This question evaluates a candidate's competency in balancing security requirements with product delivery speed, encompassing risk assessment, stakeholder management, trade-off communication, and ownership of execution and follow-through.
Behavioral & LeadershipOnsite - RobinhoodMediumSoftware EngineerImplement string-based candlestick classifier
This question evaluates string parsing, streaming input processing, numeric validation, and attention to time/space complexity in the Coding & Algorithms category, focusing on efficient single-pass parsing and O(1) extra space constraints.
Coding & AlgorithmsTechnical Screen - RobinhoodMediumSoftware EngineerMaintain Fractional Stock Inventory Across Orders
Simulate sequential customer fractional buy and sell orders, using scaled integer arithmetic to maintain the firm's remaining inventory between 0 and 1 share while tracking whole-share market executions.
Coding & AlgorithmsOnsitesimulationmathhash-table - RobinhoodMediumSoftware EngineerParse Requests and Compute Balances
This problem tests your ability to parse structured text commands, manage relational state between users, and implement transactional logic with integrity constraints.
Coding & AlgorithmsOnsiteHash MapGraphParsing - RobinhoodMediumSoftware EngineerProduce a Deterministic Course Plan
Return the lexicographically smallest valid course order from prerequisite pairs, or report a cycle. Handle duplicate edges, malformed IDs, self-dependencies, empty course sets, and large graphs with deterministic topological sorting.
Coding & AlgorithmsOnsite - RobinhoodMediumSoftware EngineerReason About Dependency Loading with Topological Sort
Tests graph construction, topological sorting (Kahn's algorithm or DFS), cycle detection, and deterministic tie-breaking for modular dependency resolution.
Software Engineering FundamentalsTechnical ScreenGraphTopological SortHeap - RobinhoodMediumSoftware EngineerWalk through project scope, ownership, and decisions
This interview question evaluates behavioral evidence, ownership, communication, trade-offs, and measurable outcomes in a realistic interview setting. A strong answer for Walk through project scope, ownership, and decisions states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Behavioral & LeadershipTechnical Screen - RobloxMediumSoftware EngineerBuild an Auto-Rotating Traffic Light in Vanilla JavaScript Without a Framework
A frontend coding question asking for a traffic light that cycles through its colors automatically, built with plain HTML, CSS, and JavaScript and no framework. It tests state machine design, timer management and cleanup, efficient DOM updates, accessibility, and how to test time-based UI code.
Software Engineering FundamentalsOnsite - RobloxHardSoftware EngineerCount Distinct Hat Assignments and Maximize Hat Points
Count valid one-hat-per-person assignments and maximize assigned-hat points with exact counts, unique hat use, and bitmask or backtracking reasoning.
Coding & AlgorithmsOnsite - RobloxMediumSoftware EngineerData Center Rack Units: Can a Centered Equipment Bay Be Reserved?
Process an online stream of rack-unit reservations and span-availability checks over an infinite 1D coordinate line, answering each availability check with the data seen so far.
Coding & AlgorithmsOnline Assessmentbinary-searchonline-queriesarrays - RobloxHardSoftware EngineerDefine success metrics and monitoring
Define success metrics and monitoring evaluates metric design, causal reasoning, experiment setup, diagnostics, SQL/statistical checks, and recommendations in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Analytics & ExperimentationOnsite - RobloxEasySoftware EngineerDesign Multi-Dimensional Request Rate Limiting
Design a distributed, low-latency rate limiting service capable of enforcing multi-dimensional limits (e.g., by user ID, IP address, and endpoint) across a large-scale gaming platform.
System DesignTechnical ScreenDistributed SystemsRate LimitingCaching - RobloxHardSoftware EngineerDesign a Played-By Summary System
Design a scalable social-proof service that tracks unique player counts per experience and computes real-time friend-intersection summaries under high write throughput and low read latency.
System DesignTechnical Screensystem-designdistributed-systemscaching - RobloxMediumSoftware EngineerDesign a Real-Time Shared To-Do List
Design a real-time collaborative to-do list supporting concurrent edits, task reordering, fast write confirmations, and seamless reconnect recovery.
System DesignTechnical ScreenReal-TimeWebSocketsDistributed Systems - RobloxMediumSoftware EngineerDesign a Scalable Like Counter
This question tests the ability to design a high-throughput, eventually consistent counting system that handles massive concurrent write volumes while maintaining low-latency read access.
System DesignOnsiteScalabilityDistributed SystemsCaching - RobloxMediumSoftware EngineerDesign a Scalable Likes System
This question tests your ability to design a high-throughput, distributed service for tracking user engagement, focusing on write-heavy loads and read-consistency trade-offs.
System DesignTechnical ScreenScalabilityDistributed SystemsCaching - RobloxHardSoftware EngineerDesign a Static Audio Detection System
This question evaluates system design and ML integration skills for building a scalable, reliable offline audio detection pipeline, including ingestion, preprocessing, STT and spectral feature extraction, rule-based post-processing, artifact persistence, and human-in-the-loop review within the ML system design domain.
ML System DesignOnsite - RobloxEasySoftware EngineerDesign a game recommendation modeling approach
This problem tests the ability to design an end-to-end recommendation engine for a massive-scale gaming platform, focusing on user-item interaction modeling and handling cold-start scenarios.
ML System DesignTechnical ScreenRecommender SystemsML DesignRetrieval - RobloxMediumSoftware EngineerDesign a rate limiter
This problem tests your ability to design a distributed rate-limiting service that maintains request counts across multiple application nodes while balancing system performance and accuracy.
System DesignTechnical ScreenScalabilityDistributed SystemsCaching - RobloxHardSoftware EngineerDesign a scheduled payment system
This question evaluates proficiency in designing a reliable, scalable scheduled payment service, testing competencies in distributed systems, API design, scheduling and execution workflows, idempotency and deduplication, time semantics, transactional consistency, security and compliance, and operational monitoring.
System DesignOnsite - RobloxMediumSoftware EngineerDesign an In-App Notification Center with Real-Time Updates and Unread Counts
A system design question about an in-app notification center that turns product events into per-user notifications, shows an unread badge and a recent list, and pushes new items to online users. It tests fan-out strategy, inbox data modeling, unread counts, real-time delivery, reliability, and client design.
System DesignOnsite - RobloxMediumSoftware EngineerDesign favorites and social game recommendations
This question tests the ability to design a scalable, low-latency system for managing user-specific lists (favorites) and integrating real-time social signals into a game recommendation engine.
System DesignOnsiteScalabilityCachingSocial Graphs - RobloxMediumSoftware EngineerDesign in-game payment wallet system
Design in-game payment wallet system evaluates requirements, scale assumptions, API/data design, architecture, trade-offs, failure modes, and rollout in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
System DesignTechnical Screen - RobloxHardSoftware EngineerDesign real-time game matchmaking service
This question evaluates a candidate's competence in designing scalable, low-latency distributed systems and matchmaking algorithms, including skills in queue management, skill-based matching, regional sharding, SLO-driven latency targets, consistency models, failure handling, and monitoring.
System DesignOnsite
Robinhood
Roblox