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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
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- 546
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- 11
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Showing 3871–3900 of 5874 results
- OpenAIMediumSoftware EngineerClarify and Design Social-Graph Milestones
Clarify ambiguous social-graph milestones before designing follow and unfollow operations, consistent snapshots, and user recommendations. The discussion tests directed-edge semantics, snapshot guarantees, recommendation-policy choices, exclusions, deterministic tie rules, scale assumptions, and contract-focused testing.
Software Engineering FundamentalsOnsite - OpenAIHardSoftware EngineerCompute Infection Time in a Grid
This problem tests your ability to model state propagation in a 2D grid using Breadth-First Search (BFS) to determine the time required for a dynamic condition to cover all reachable nodes.
Coding & AlgorithmsTechnical ScreenBFSGraphSimulation - OpenAIMediumSoftware EngineerCompute Plant Infection Stabilization
This problem tests your ability to simulate state propagation across a grid over discrete time steps and determine the minimum number of interventions required to contain an infection.
Coding & AlgorithmsTechnical ScreenSimulationGridBacktracking - OpenAIMediumSoftware EngineerCompute Plant Infection Time
This problem tests your ability to model a grid-based propagation process using Breadth-First Search (BFS), specifically handling multi-source initialization and obstacle avoidance.
Coding & AlgorithmsTechnical ScreenBFSGraphGrid - OpenAIMediumSoftware EngineerCompute infection spread time
This problem tests your ability to model a spreading process on a 2D grid using a multi-source Breadth-First Search (BFS) to determine the time required for a state to propagate across the entire space.
Coding & AlgorithmsOnsiteBFSGraphsGrid - OpenAIHardSoftware EngineerContiguous Extent Allocator for a Storage Volume, Then O(log n)
Build an allocator that hands out contiguous runs of blocks on a fixed-size volume and takes them back with coalescing, first with a simple sorted list and then with logarithmic reserve and release. Tests splitting/merging logic, choosing indexes for size and neighbor lookups, and keeping them consistent.
Software Engineering FundamentalsTechnical Screenallocatordata-structuresbalanced-bst - OpenAIMediumSoftware EngineerCount Connected Friend Groups
Determine the number of connected components in an undirected graph represented as an adjacency matrix using graph traversal or disjoint set union.
Coding & AlgorithmsTechnical Screengraphdfsbfs - OpenAIHardSoftware EngineerCount Events in a Trailing 15-Minute Window with a Fixed-Size Ring Buffer
Implement an event counter that returns how many events occurred in the trailing 15 minutes, using a fixed-size ring buffer of per-second buckets so memory stays bounded at any event rate. It tests circular buffers, stale-slot detection, window boundaries, late events and thread safety.
Software Engineering FundamentalsOnsite - OpenAIMediumSoftware EngineerCount Machines and Recover a Distributed Tree Topology
Implement a distributed tree discovery and aggregation protocol that counts reachable machines, recovers edges, handles network retries, detects unreachable subtrees, and validates tree invariants.
Software Engineering FundamentalsTechnical ScreenDistributed SystemsTreeGraph Traversal - OpenAIHardSoftware EngineerCount Ordered Four-Shop Road Paths That Visit One Shop of Each Type
Count the ordered routes through a town's road network that visit exactly one shop of each of four types, where consecutive shops must share a direct road and a route and its reverse count separately. Tests graph modeling, path enumeration under type constraints and careful counting on small graphs.
Coding & AlgorithmsOnline Assessment - OpenAIMediumSoftware EngineerDebug a Machine Learning Pipeline
This question evaluates a candidate's ability to diagnose production machine learning failures, covering competencies in data quality, data and concept drift detection, model versioning and deployment checks, and operational debugging within an MLOps context.
Machine LearningTechnical Screen - OpenAIHardSoftware EngineerDebug a failing ML classifier
This question evaluates a candidate's ability to diagnose a poorly generalizing ML classifier, testing practical knowledge of data leakage, feature drift, and model calibration. It assesses applied machine learning debugging skills — including cross-validation design and error analysis — commonly tested in senior engineering and ML roles.
Machine LearningTechnical Screen - OpenAIMediumSoftware EngineerDesign Bakery Chain Card Payments With Tips and Nightly Settlement
Design the payment system for a bakery chain's counter terminals, where a card is authorized for the purchase, a tip is added afterward, and each location's transactions are captured together in a nightly settlement batch that must scale as the chain grows.
System DesignOnsitesystem-designpaymentsidempotency - OpenAIMediumSoftware EngineerDesign CI/CD Build Caching
This problem evaluates your ability to design a distributed caching system for CI/CD pipelines, focusing on cache key strategies, invalidation, and storage scalability.
System DesignTechnical ScreenDistributed SystemsCI/CDCaching - OpenAIHardSoftware EngineerDesign Command Dispatch and Telemetry Reconciliation for Unreliable Devices
Design a resilient control plane and telemetry reconciliation system for millions of intermittently connected edge devices, ensuring safe command execution, idempotency, and accurate state tracking despite network unreliability.
System DesignTechnical ScreenDistributed SystemsIoTEdge Computing - OpenAIMediumSoftware EngineerDesign First-Fit and Best-Fit Memory Allocation
Design an in-memory heap allocator supporting first-fit and best-fit allocation, block splitting, adjacent free block coalescing, and safe handle validation to prevent stale or forged free operations.
Software Engineering FundamentalsTechnical ScreenMemory ManagementData StructuresLinked List - OpenAIMediumSoftware EngineerDesign GPU Scheduling for a Video Generation Platform
This question tests your ability to design a distributed job scheduling system that manages heterogeneous GPU resources for computationally expensive, variable-length video generation tasks.
System DesignOnsiteGPU SchedulingDistributed SystemsLatency - OpenAIHardSoftware EngineerDesign GPU credit allocator
A multi-tenant GPU credit allocation system design (OpenAI software-engineer system-design screen): track and deduct GPU credits in real time across many nodes, issue/transfer/spend credits via idempotent APIs, and enforce budgets, hierarchical quotas, rate limits, and fair-share with scheduler integration. Covers prepaid vs postpaid, an immutable double-entry ledger with reservations, overspend prevention, failure recovery, scaling, and observability.
System DesignTechnical Screen - OpenAIHardSoftware EngineerDesign IDE Sandbox and Payments
This question evaluates system design competencies such as distributed systems architecture, scalability, isolation and security, API and state-machine design, storage and synchronization, resiliency, observability, and compliance applied to two domains: a cloud IDE sandbox and a payment processing backend, with domain: System Design.
System DesignOnsite - OpenAIHardSoftware EngineerDesign Online Chess Matchmaking
This question tests the ability to design a distributed, low-latency matchmaking system that balances player skill (MMR), wait time, and network latency under high concurrency.
System DesignTechnical ScreenScalabilityConcurrencyDistributed Systems - OpenAIMediumSoftware EngineerDesign Online Chess Matchmaking and Clocks
This question tests your ability to design a real-time game backend, focusing on low-latency state synchronization, fair matchmaking, and reliable clock management in a distributed environment.
System DesignTechnical ScreenReal-timeConcurrencyWebSockets - OpenAIMediumSoftware EngineerDesign Payment Authorization, Capture, and Batch Settlement
Design a resilient payment processing platform supporting two-phase payment operations (authorize and capture), double-entry ledgering, and asynchronous batch settlement with external financial gateways.
System DesignTechnical ScreenPaymentsDistributed SystemsLedger - OpenAIHardSoftware EngineerDesign Photo Storage with SHA-256 Content Deduplication and Safe Deletion
Design a photo storage service that deduplicates identical uploads by their SHA-256 content hash. Cover the upload flow with server-side verification, concurrent identical uploads, deletion with reference counting and garbage collection, and the privacy risks of deduplicating across users. It tests content-addressed storage design.
System DesignOnsite - OpenAIHardSoftware EngineerDesign Power-Grid Device Monitoring over Unreliable Networks: Dedup and Late Events
Design a monitoring platform for power-grid devices that report readings and upload logs over unreliable public networks. Ingestion must be idempotent, deduplicate retransmissions, handle out-of-order and late events and accept batched uploads. It tests IoT ingestion, event-time processing and resilience to reconnect storms.
System DesignOnsite - OpenAIHardSoftware EngineerDesign Real-Time Electricity Monitoring and Policy Control
Design a distributed real-time electricity monitoring and policy actuation system that ingests high-throughput telemetry, evaluates dynamic load-shedding policies with hysteresis, and reliably issues auditable commands to edge devices.
System DesignTechnical ScreenStream ProcessingIoTDistributed Systems - OpenAIMediumSoftware EngineerDesign Restart Strategy for Oracle Solver
This question tests the ability to optimize restart intervals for a randomized algorithm with heavy-tailed runtime distributions, balancing the trade-off between progress and computation waste.
Machine LearningHR ScreenProbabilistic ModelingAlgorithmsOptimization - OpenAIMediumSoftware EngineerDesign Slack-like messaging platform
This question evaluates a candidate's ability to design scalable, secure, real-time messaging systems, testing competencies in distributed systems, data modeling, API design, storage and sharding strategies, search indexing, and notification delivery.
System DesignTechnical Screen - OpenAIMediumSoftware EngineerDesign Slack-like multi-tenant global messaging system
This question tests the ability to design a global, multi-tenant messaging platform that handles high-concurrency real-time delivery, data isolation, and low-latency synchronization across distributed environments.
System DesignOnsiteDistributed SystemsMulti-tenancyReal-time - OpenAIMediumSoftware EngineerDesign Video Generation Orchestration
This system design question tests a candidate's ability to architect asynchronous, distributed job-orchestration pipelines at scale. It evaluates practical knowledge of durable queues, state machines, reliability patterns like the outbox and idempotency, and trade-offs between throughput and latency in GPU-constrained systems.
System DesignTechnical Screen - OpenAIHardSoftware EngineerDesign a CI/CD pipeline with scheduler
An OpenAI software-engineering system design interview question: design a production-grade CI/CD pipeline for a large microservices monorepo, end to end. It spans source-control triggers, build and artifact management, layered testing with flaky-test handling, progressive deployment and rollback, observability, supply-chain security, and — the differentiator — the job scheduler that orchestrates pipeline steps (DAG modeling, concurrency, priorities, retries, caching, rate limiting) plus its data stores, queues, APIs, schemas, multi-tenant fairness, KPIs/SLOs, and failure handling.
System DesignTechnical Screen
OpenAI