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System Design 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.
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Showing 481–510 of 721 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 - 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 - 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 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 - 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 - 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 - OpenAIHardMachine Learning EngineerDesign a regional surge pricing strategy
This question evaluates skills in designing real-time surge pricing systems, assessing competencies in machine learning modeling, control and pricing logic, data engineering, operational robustness, explainability, and monitoring within the System Design domain.
System DesignOnsite - OpenAIEasySoftware EngineerDesign a sandboxed cloud IDE
This question evaluates a candidate's competency in designing multi-tenant distributed systems with strong isolation and sandboxing, runtime lifecycle management, real-time output/log streaming, data persistence, autoscaling, and observability.
System DesignOnsite - OpenAIHardMachine Learning EngineerDesign a search query autocomplete system
This question evaluates a candidate's ability to design a real-time, low-latency search autocomplete system, exercising competencies in architecture, indexing and serving, ranking and personalization, typo-tolerance, multilingual support, abuse prevention and privacy-aware data handling; it is categorized under System Design and emphasizes practical application with architectural-level conceptual reasoning. It is commonly asked to assess how candidates balance stringent latency and scalability requirements with personalization and trending signals, robustness to input errors and multiple languages, and metrics-driven trade-offs across caching, ranking and monitoring.
System DesignOnsite - OpenAIMediumSoftware EngineerDesign a text-to-video GPU job scheduler with one GPU per task and fair queueing
Design a GPU job scheduler for a text-to-video generation service where each task runs on a single GPU and users share capacity through fair queueing. It tests job store design, fairness by GPU time rather than task count, leases and retries, and failure handling across workers, GPUs and the scheduler.
System DesignOnsite - OpenAIMediumSoftware EngineerDesign an Asynchronous Text-to-Video Generation Service
This question tests the ability to design a high-latency, asynchronous job-processing pipeline with a focus on fault tolerance, job state management, and reliable resource handling.
System DesignOnsiteAsync ProcessingScalabilityJob Queues - OpenAIHardSoftware EngineerDesign an Online Chess Platform: Elo Matchmaking, WebSocket Moves, Game Clocks
Design an online chess platform: match players of similar Elo rating quickly, deliver moves in real time over WebSocket connections, and enforce fair game clocks despite network latency and disconnections. It tests matchmaking, stateful real-time architecture, server-authoritative timing and failover.
System DesignOnsite - OpenAIMediumSoftware EngineerDesign an Online Chess Service from Launch to Scale
This problem tests the ability to design a real-time, stateful gaming system, focusing on concurrency control, low-latency communication, and fault tolerance.
System DesignOnsiteReal-timeConcurrencyWebSockets - OpenAIHardSoftware EngineerDesign an Online Multiplayer Chess Service with Real-Time Moves
Design an online chess service where two remote players play live games, every move is validated and delivered to the opponent immediately, and results are recorded. It tests authoritative game state, real-time transport, fair clocks, move ordering, recovery of games in progress after failures, and scaling to many concurrent games and spectators.
System DesignOnsite - OpenAIHardSoftware EngineerDesign an SSH-Based Cloud Development Environment
This question tests your ability to design a distributed system that manages stateful, long-running compute resources while ensuring isolation, high availability, and secure remote access.
System DesignOnsiteDistributed SystemsCloud InfrastructureSecurity - OpenAIMediumSoftware EngineerDesign coffee-shop card payments with tips and nightly batch settlement at scale
Design a card payment system for coffee shops where purchases are authorized at the counter, tips are added afterwards, and transactions settle in a nightly batch. The discussion centers on scaling nightly settlement, along with idempotent APIs, failure handling and reconciliation against processor reports.
System DesignOnsite - OpenAIMediumSoftware EngineerDesign power grid device monitoring over an unreliable public internet
Design a monitoring system for power grid field devices that report their status over an unreliable public internet. It tests store-and-forward reporting, idempotent ingestion of late and duplicate data, telling silent devices from failed ones, alerting, and security for critical infrastructure.
System DesignOnsite - OpenAIMediumSoftware EngineerDesign webhook, POI, chat, CI/CD, payments
This question evaluates proficiency in distributed system design, covering scalability, availability, durability, data modeling, geospatial indexing, event-driven delivery, API design, fault tolerance, security, and operational monitoring for high-throughput backend services.
System DesignOnsite - OpenAIMediumSoftware EngineerMonitor Devices Over an Unreliable Network
Design an edge-to-cloud device monitoring system that accurately tracks device health and liveness across flaky, high-latency networks without falsely reporting absolute state.
System DesignOnsitesystem-designdistributed-systemsiot - OptiverHardSoftware EngineerDesign low-latency trading infrastructure
Design an end-to-end low-latency market making and execution architecture split between an exchange-colocated environment and a remote operational office.
System DesignOnsiteLow LatencyHigh-Frequency TradingNetworking - OracleMediumBackend EngineerDesign a Distributed Rate Limiter
This problem tests the ability to design a scalable, low-latency distributed system for enforcing traffic quotas across multiple geographic regions with considerations for consistency and burst handling.
System DesignOnsiteDistributed SystemsRate LimitingScalability - OracleMediumSoftware EngineerDesign a Five-Minute Top-K Error Log Service
Design a fault-tolerant, high-throughput log aggregation service that identifies and ranks the top-K microservices with the highest error counts over a sliding five-minute window.
System DesignOnsiteStream ProcessingTop-KDistributed Systems - OracleMediumBackend EngineerDesign a High-Volume Healthcare Data Ingestion Pipeline
This question tests the ability to design a resilient, high-throughput ETL pipeline for sensitive and messy healthcare data, focusing on fault isolation, data integrity, and architectural scalability.
System DesignOnsiteETLData PipelineScalability - OracleMediumSoftware EngineerDesign a Sliding-Hour Top-100 User Event Pipeline
Design a real-time event-time aggregation pipeline to compute the top 100 most active users over a trailing 60-minute sliding window at scale.
System DesignOnsiteStream ProcessingTop-KSliding Window - OracleMediumSoftware EngineerDesign a Software Load Balancer
This problem tests the ability to architect a scalable, fault-tolerant entry point for distributed systems, focusing on request routing, health monitoring, and concurrency management.
System DesignOnsiteLoad BalancingNetworkingDistributed Systems - OracleMediumSoftware EngineerDesign a Synchronously Replicated Hash Map
Design an in-memory key-value storage system utilizing active-passive synchronous replication where writes must commit on both nodes or fail atomically.
System DesignOnsitedistributed-systemssystem-designreplication
OpenAI
Optiver
Oracle