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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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Showing 3931–3960 of 5874 results
- OpenAIMediumSoftware EngineerDesign a Payment Lifecycle from Hold to Charge and Settlement
This problem tests the design of a distributed, idempotent payment processing system that ensures data consistency and financial integrity across asynchronous state transitions.
System DesignOnsiteDistributed SystemsIdempotencyReliability - OpenAIMediumSoftware EngineerDesign a Payment Orchestration System
Design a resilient merchant-side payment orchestration platform that routes transactions across multiple payment service providers (PSPs) while enforcing strict amount invariants, idempotent state transitions, and auditability.
System DesignOnsitePaymentsDistributed SystemsIdempotency - OpenAIMediumSoftware EngineerDesign a Payment Processing Service (Merchant to Payment Provider)
This question tests the ability to design a reliable, fault-tolerant distributed system for handling financial transactions, focusing on idempotency, atomicity, and consistent state transitions.
System DesignTechnical ScreenDistributed SystemsAPI DesignFinancial Systems - OpenAIHardSoftware EngineerDesign a Payment Processing System
This question tests the ability to design a distributed payment processing system that guarantees atomicity and consistency under high concurrency and partial network failures.
System DesignOnsiteDistributed SystemsConsistencyIdempotency - OpenAIHardSoftware EngineerDesign a Payment Processing System with Exactly-Once Charging
This question tests the ability to design a fault-tolerant payment system that handles distributed transactions, ensures idempotency, and reconciles state with external gateways.
System DesignTechnical ScreenDistributed SystemsIdempotencyTransactions - OpenAIMediumSoftware EngineerDesign a Payment Processor with Holds, Charges, and Network Batches
Design a hold-and-charge payment processor with honest asynchronous results, durable deduplication, incremental network batches, and safe acknowledgment recovery.
System DesignTechnical Screen - OpenAIEasySoftware EngineerDesign a Payment System
This system design question evaluates a candidate's ability to architect a reliable backend payment flow, including idempotent request handling, transactional data modeling, and reconciliation with external processors. It is commonly asked to assess practical distributed systems skills around failure handling, consistency, and scalability under real-world conditions, testing applied architectural reasoning rather than pure theory.
System DesignTechnical Screen - OpenAIMediumSoftware EngineerDesign a Payment System That Charges Customers Through an External Payment Provider
A system design interview question asking you to design a payment system that charges customers through an external payment provider. It tests exactly-once charging under retries and timeouts, payment state machines, ledger and reconciliation design, webhook handling, and failure recovery.
System DesignOnsite - OpenAIHardSoftware EngineerDesign a Payment System: Holds and Captures, Batch Charges, Reconciliation, Idempotency
Design a payment system that places holds and captures final amounts, submits charges in batches, reconciles internal records against processor settlement reports, and never double-charges when calls are retried. It tests payment state machines, double-entry ledgers, idempotency and reconciliation.
System DesignOnsite - OpenAIMediumSoftware EngineerDesign a Photo Storage Service That Deduplicates Uploads by SHA-256 Content Hash
A system design question about a photo service that supports upload, download and delete while keeping only one stored copy of any content with the same SHA-256 hash. It tests content-addressed storage, reference tracking, safe deletion under concurrent uploads, and the security risks of deduplicating across users.
System DesignTechnical Screen - OpenAIMediumSoftware EngineerDesign a Real-Time Multiplayer Typing Race with Matchmaking and Spectators
A system design question: build a real-time multiplayer typing race where players matched by language into races of 2 to 8 type the same text, see each other's progress and errors live, freeze for one second per error, and can be watched by spectators. It tests matchmaking, server-authoritative real-time state, fan-out to spectators and fairness under network latency.
System DesignTechnical Screen - OpenAIHardSoftware EngineerDesign a Real-Time Multiplayer Typing Race with Typo Freezes and Fair Matchmaking
Design a real-time multiplayer typing race for 2 to 8 players in which the first player to type a generated passage wins and every wrong letter freezes that player for one second. The discussion covers the freeze mechanism, matchmaking, ranking players by score, and keeping races fair when players have different network delays.
System DesignTechnical Screen - OpenAIMediumSoftware EngineerDesign a Real-Time Online Chess Platform
This question tests your ability to design a low-latency, stateful distributed system that handles real-time bidirectional communication and ensures strict move consistency.
System DesignTechnical ScreenWebSocketsConcurrencyReal-time - OpenAIMediumSoftware EngineerDesign a Real-Time Trivia Battle Royale Platform with Live Spectating
System design question about a real-time trivia battle royale in which dozens to a hundred or more players per room answer timed rounds, the wrong and slowest are eliminated, and spectators watch live leaderboards. It tests sharding by room, authoritative round settlement, fair answer timing, recovery from a server failure mid-round, and spectator isolation.
System DesignOnsite - OpenAIMediumSoftware EngineerDesign a Reliable Payment Processing System
Design a reliable payment-processing service that prevents duplicate charges and preserves an auditable state history through retries and partial failures. Cover idempotency, exact money representation, timeout ambiguity, asynchronous callbacks, reconciliation, state transitions, partitioning, and operational controls.
System DesignOnsite - OpenAIHardSoftware EngineerDesign a Retrieval-Augmented Generation (RAG) system
This question tests the ability to design an end-to-end Retrieval-Augmented Generation (RAG) system, focusing on balancing retrieval accuracy, latency, data freshness, and system reliability.
ML System DesignTechnical ScreenRAGLLMVector Databases - OpenAIMediumSoftware EngineerDesign a Slack-Like Messaging System
This System Design question evaluates a candidate's ability to architect a scalable, durable real-time messaging system, testing skills in distributed systems, data modeling, API design, persistence versus low-latency delivery, ordering guarantees, missed-message recovery, notifications, and operational scaling.
System DesignTechnical Screen - OpenAIHardSoftware EngineerDesign a Slack-like real-time messaging system
This problem tests your ability to design a distributed, low-latency messaging system that handles concurrent message delivery, persistence, and synchronization across multiple devices.
System DesignTechnical ScreenScalabilityWebSocketsDatabase - OpenAIMediumSoftware EngineerDesign a Sora-Style Video Generation Service with Fair Queueing and Cancellation
A system design question about building a Sora-style text-to-video generation service in which every generation task runs on exactly one GPU. It tests task lifecycle and dispatch design, fair sharing of GPU time across many users, and cancellation of queued and running tasks, including whether a direct RPC to the worker is enough.
System DesignOnsite - OpenAIHardSoftware EngineerDesign a Text-to-Video Generation Platform (Sora-style)
This problem evaluates your ability to design a distributed ML infrastructure that handles high-latency, resource-intensive inference jobs while ensuring scalability, reliability, and content safety.
ML System DesignOnsiteDistributed SystemsML InfrastructureTask Queues - OpenAIMediumSoftware EngineerDesign a Text-to-Video Generation Service
This question tests the ability to design a scalable, reliable asynchronous inference pipeline for resource-intensive generative models, focusing on task orchestration, GPU scheduling, and latency management.
ML System DesignTechnical ScreenML-SystemsDistributed-SystemsGPU-Orchestration - OpenAIHardSoftware EngineerDesign a Text-to-Video Generation System
This question evaluates a candidate's competency in designing scalable ML inference platforms, including GPU resource management and scheduling, asynchronous job orchestration and state-machine-driven job lifecycles, failure classification and recovery, artifact storage, rate limiting, and monitoring for quality and latency.
ML System DesignOnsite - OpenAIMediumSoftware EngineerDesign a Tier-Aware AI Video Generation Service
This problem tests your ability to design a distributed, asynchronous task processing system that balances resource fairness, reliability in the face of compute failures, and tiered prioritization.
System DesignTechnical ScreenDistributed SystemsQueuesTask Scheduling - OpenAIMediumSoftware EngineerDesign a Time-Windowed GPU Credit Ledger
Design an in-memory credit ledger that manages time-windowed resource grants and consumptions with out-of-order event ingestion, deterministic allocation, and balance reconciliation.
Software Engineering FundamentalsTechnical ScreenData StructuresSimulationIntervals - OpenAIMediumSoftware EngineerDesign a URL Shortener
This question tests your ability to design a highly scalable, distributed URL shortening service, focusing on database schema design, request routing, and efficient short-code generation.
System DesignOnsiteScalabilityCachingDatabase Sharding - OpenAIHardSoftware EngineerDesign a URL shortening service
This problem tests your ability to design a distributed, high-scale URL shortening service, focusing on data modeling, collision-resistant ID generation, and performance optimization via caching.
System DesignOnsiteDistributed SystemsDatabase ShardingCaching - OpenAIHardSoftware EngineerDesign a User-Respecting Smart-Grid Controller
Design a distributed demand-response and curtailment controller for an electrical grid that sheds load during emergencies while strictly respecting user preferences, device criticalities, and fairness constraints.
System DesignTechnical Screensystem-designdistributed-systemsiot - OpenAIMediumSoftware EngineerDesign a Video Generation Service with GPU Fleet Management
Tests the ability to design an end-to-end distributed ML inference system for compute-intensive video generation, focusing on GPU scheduling, job lifecycle management, fault tolerance, and cost efficiency.
ML System DesignTechnical ScreenGPU SchedulingDistributed SystemsFault Tolerance - OpenAIMediumSoftware EngineerDesign a chatbot (system design)
This question evaluates system design skills for ML-powered chatbots with a front-end focus, testing understanding of client-side privacy and storage lifetimes, streamed response delivery, stateless relay architectures, authentication boundaries, rate limiting, and failure-mode handling.
ML System DesignTechnical Screen - OpenAIHardSoftware EngineerDesign a crossword puzzle solver system
This problem tests the ability to design an efficient search and constraint-solving system for crossword puzzles, requiring optimized data structures for prefix lookups and a backtracking strategy to handle search space pruning.
System DesignTechnical ScreenBacktrackingTrieConstraint Satisfaction
OpenAI