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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.
- 9403
- Questions
- 546
- Companies
- 11
- Topics
- 8
- Languages
Showing 361–390 of 1311 results
- DatabricksMediumSoftware EngineerDesign a stock order manager
Design an equity Order Management System (OMS) that manages order lifecycles, ensures idempotent broker interactions, and guarantees state reconciliation under distributed failures.
System DesignTechnical Screensystem-designdistributed-systemsfintech - DatabricksHardSoftware EngineerDesign a thread-safe bounded queue
This question evaluates skills in concurrent programming, synchronization primitives, and designing thread-safe bounded data structures that support blocking operations with timeouts, fairness, and backpressure.
System DesignHR Screen - DatabricksMediumSoftware EngineerDesign an Online Book Seller Platform
Design an end-to-end e-commerce platform for selling books, balancing read-heavy catalog exploration with strictly consistent inventory reservation and fault-tolerant checkout workflows.
System DesignOnsiteE-CommerceDistributed SystemsTransactions - DatabricksHardSoftware EngineerDesign an Online Bookstore
This problem tests your ability to design a distributed e-commerce platform by focusing on consistency models for inventory, scalable search architecture, and robust order processing.
System DesignOnsiteMicroservicesDistributed SystemsConsistency - DatabricksMediumSoftware EngineerDesign an online bookstore: DB insert succeeds but SQS publish fails, and duplicate messages
System design question about an online bookstore whose order service inserts orders into a database and then publishes messages to Amazon SQS. Probes what should happen when the insert succeeds but the publish fails, how to keep the database and queue consistent across crashes, and how consumers avoid duplicate processing under at-least-once delivery.
System DesignTechnical Screen - DatabricksMediumSoftware EngineerDesign bookstore and chat messaging systems
This question tests the ability to design two distinct systems: a reliable transactional e-commerce inventory service and a low-latency real-time chat application, focusing on appropriate database choices and communication protocols.
System DesignOnsiteDistributed SystemsDatabasesReal-time - DatabricksHardSoftware EngineerDesign concurrent range-aware file caching client
This interview question evaluates requirements, scale assumptions, API/data design, architecture, trade-offs, failure modes, and rollout in a realistic interview setting. A strong answer for Design concurrent range-aware file caching client states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
System DesignHR Screen - DatabricksHardSoftware EngineerIdentify and handle race conditions
This question evaluates understanding of concurrency, race conditions, synchronization mechanisms, and performance trade-offs in designing thread-safe in-memory data structures like key-value stores and hit counters.
System DesignTechnical Screen - DatabricksMediumSoftware EngineerLowest-Price Book Aggregator Fanning Out to Hundreds of Async Bookstores
Design a middleman service that takes an ISBN, bid price and payment method, queries several hundred asynchronous bookstores for the lowest price, and then orders, returns the price or reports no stock. Deep dives cover partial results and circuit breakers, caching against thundering herds, and order-and-charge consistency.
System DesignOnsite - DatabricksMediumSoftware EngineerSingle-Machine Cache with WAL Persistence, Sharded Locks and LRU
Design and write pseudocode for a single-machine in-memory cache behind a web service, then add write-ahead-log persistence, shard it to cut lock contention, shrink critical sections, find deadlocks by inspection, and explain LRU eviction built from a linked list and a hash map.
System DesignOnsite - DatabricksMediumSoftware EngineerThread-Safe Durable Event Writer Shared by Thousands of Threads
Design a thread-safe DataWriter whose push method durably appends opaque records of up to 1 KB to one local file while thousands of threads call it at once. Tests durability contracts, batching disk syncs across callers, crash-safe record framing and handling of failed writes.
System DesignOnsite - DatadogHardSoftware EngineerDesign log-query stream processor
Design log-query stream processor 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 - DecagonHardSoftware EngineerDesign a Durable Delayed Task Scheduler
Design a distributed, durable task scheduler capable of scheduling millions of tasks to execute at exact future timestamps with high precision, at-least-once delivery, and automatic fault recovery.
System DesignTechnical Screensystem-designdistributed-systemstask-scheduler - DecagonMediumSoftware EngineerDesign an AI Gateway
Design a high-throughput, multi-tenant AI Gateway that provides a unified API, intelligent routing, token-aware rate limiting, and observability across multiple upstream LLM providers.
System DesignTechnical ScreenAPI GatewayLLM InfrastructureRate Limiting - DecagonMediumSoftware EngineerDesign the Security Architecture for an LLM Chatbot Product
A system design question on securing a chatbot built on a large language model that talks with people outside the company. It tests threat modeling for prompt injection and data leakage, user authentication and tool authorization outside the model, tenant isolation, sensitive-data handling, abuse controls, auditing and incident response.
System DesignOnsite - DigitaloceanMediumSoftware EngineerDesign a Multi-Organization Advertising Platform with Performance Statistics
Design ad management, serving, event collection, deduplicated statistics, and fair performance comparisons across organizations and campaigns.
System DesignOnsite - DiscordEasySoftware EngineerDesign Slack-like chat system
An onsite system-design interview question asking you to design the chat subsystem for a Slack/Discord-like app: workspaces, channels, 1:1 and group DMs, full message history, real-time updates, and edit/delete. It tests data modeling, storage and partitioning, fanout strategy, real-time WebSocket delivery, and per-conversation ordering and consistency.
System DesignOnsite - DiscordHardData EngineerDesign Video Call Analytics Tables
This question evaluates data modeling and analytics competencies including event schema design, dimensional modeling (facts and dimensions), ETL/cleaning and deduplication, and time-windowed SQL aggregation.
System DesignOnsite - DiscordMediumSoftware EngineerDesign a TCP Discord-like chat server
This question evaluates a candidate's skills in system design, TCP-based protocol design, real-time messaging, data modeling, persistence, session/reconnection handling, and concurrency control for backend services.
System DesignOnsite - DiscordMediumSoftware EngineerDesign leader election using Redis leases
This question evaluates a candidate's understanding of distributed coordination and leader election using a central in-memory datastore, focusing on lease-based leadership, failover, and correctness under partitions and clock skew.
System DesignOnsite - DisneyEasyData EngineerData Pipeline Design for Cloud and Hybrid On-Prem Environments on AWS and Azure
A senior data engineering design question: build a data pipeline from operational sources to analytics on one cloud, then rework it for a hybrid on-premises and cloud environment and for both AWS and Azure. It tests tool selection and trade-offs, ingestion and storage design, data quality, security and portability.
System DesignOnsite - DisneyMediumSoftware EngineerDesign a Flash Sale with a Virtual Queue and Exact Inventory
Design a high-scale ticketing and merchandise flash-sale platform featuring a virtual waiting room, controlled admission rate, strictly zero-oversell inventory reservation, and idempotent checkout.
System DesignOnsiteDistributed SystemsConcurrencyCaching - DisneyMediumSoftware EngineerDesign a Twitter-like microblogging platform
This problem tests your ability to design a distributed system capable of handling high-throughput write operations, efficient read-heavy feed generation, and the trade-offs between system consistency and availability.
System DesignOnsiteScalabilityCachingDistributed Systems - DisneyMediumData EngineerDesign a clickstream ingestion and aggregation pipeline for billions of events per day
Design an end-to-end clickstream pipeline that ingests roughly one billion telemetry events per day from web, mobile, and TV clients and serves both near-real-time dashboards and accurate finalized daily aggregates without lagging. The question covers staged architecture and back-of-envelope sizing, a durable partitioned log for back-pressure, event-time windowing with watermarks and allowed lateness, late-arriving data and the provisional-to-finalized lifecycle, exactly-once deduplication in Flink versus Spark Structured Streaming, autoscaling on consumer lag, hot-partition key skew, high-cardinality DAU/MAU with HyperLogLog, and reprocessing after a logic bug. A common Disney data engineer online assessment system design question.
System DesignOnline Assessment - DisneyEasySoftware EngineerDesign a frontend shopping cart and feature flags
This question evaluates frontend system-design skills including client-side state management, synchronization and conflict-resolution strategies, caching and offline resilience, performance for large carts, observability, and feature-flag/remote-config design for targeted rollouts and experiments.
System DesignOnsite - DisneyHardSoftware EngineerDesign a global multi-game leaderboard
This question evaluates a candidate's ability to design a scalable, real-time distributed leaderboard service, testing skills in API design, data modeling, ranking algorithms, ingestion and read-path architecture, caching, sharding, consistency-versus-latency trade-offs, idempotency, anti-cheat measures, and disaster recovery.
System DesignOnsite - DockerMediumSoftware EngineerDesign a container image registry
This problem tests your ability to design a distributed, content-addressable storage system that handles large binary blobs and metadata while optimizing for read/write performance and storage efficiency.
System DesignTechnical ScreenDistributed SystemsStorageScalability - DoorDashMediumSoftware EngineerDebug round-robin request router
This interview question evaluates requirements, scale assumptions, API/data design, architecture, trade-offs, failure modes, and rollout in a realistic interview setting. A strong answer for Debug round-robin request router states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
System DesignTechnical Screen - DoorDashHardSoftware EngineerDeep-dive a project architecture
An open-ended DoorDash software-engineer system-design screen: pick a real project and deep-dive its architecture end to end. Candidates draw the diagram, state invariants, walk read/write paths, justify storage and trade-offs, capacity-plan, cover reliability/security/observability with SLOs, recount a real incident, and propose a quantified 10x-traffic plan. Includes a full worked example built around a real-time delivery dispatch and live order-tracking service.
System DesignTechnical Screen - DoorDashMediumSoftware EngineerDesign API that aggregates three downstream APIs
This question evaluates a candidate's ability to design an API aggregator, covering skills in service orchestration, fault tolerance, latency and SLO management, error handling, and observability for distributed HTTP/JSON services.
System DesignTechnical Screen
Databricks
Datadog
Decagon
Discord
Disney
DoorDash