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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 181–210 of 721 results
- DatabricksMediumBackend EngineerDesign a Distributed File System, Scoping the Requirements Yourself
Design a distributed file system from a one-line prompt, driving the scoping of workload, semantics, scale and durability yourself. Tests separating metadata from data, block replication and placement, read and write paths, failure recovery, and scaling the namespace for a staff-level backend role.
System DesignOnsite - DatabricksHardSoftware EngineerDesign a Durable Concurrent Event Writer
Design a high-throughput, thread-safe embedded log writer that safely batches and persists records from thousands of concurrent producer threads into an append-only file.
System DesignOnsiteStorage SystemsConcurrencyWrite-Ahead Log - DatabricksHardSoftware EngineerDesign a Hierarchical File System
This question tests the ability to design a distributed file system namespace capable of handling millions of files and directories with strong consistency and high availability.
System DesignOnsiteDistributed SystemsMetadataScalability - DatabricksMediumSoftware EngineerDesign a Shared, Crash-Safe Telemetry Buffer for Thousands of Worker Threads
Design a single, thread-shared component that lets up to 4,000 worker threads inside one process append small telemetry records to one local file, durably and without a disk sync per call. Tests group-commit concurrency design, a crash-safe on-disk record format, and backpressure reasoning.
System DesignOnsiteconcurrencydurabilitysystem-design - DatabricksMediumSoftware EngineerDesign a Slack-Like Messaging System
Tests your ability to architect a scalable, real-time messaging platform like Slack, focusing on connection handling, fan-out delivery, channel message ordering, and presence management.
System DesignOnsiteDistributed SystemsWebSocketsPub/Sub - DatabricksMediumSoftware EngineerDesign a Thread-Safe Buffered Writer with a Background Flush Thread
Tests the ability to design a high-throughput, thread-safe buffering system that decouples client write operations from high-latency storage I/O using concurrent synchronization, backpressure, and background worker threads.
System DesignOnsiteConcurrencyMultithreadingI/O - DatabricksMediumSoftware EngineerDesign a Visa-Style Card Payment Processing System
Design a Visa-style card payment system, choosing between the card network and a merchant-side scope. Tests real-time authorization routing to issuers, idempotent handling of retries and reversals, clearing and settlement with an auditable ledger, fraud checks, and multi-region availability.
System DesignOnsite - DatabricksHardSoftware EngineerDesign a digital game shop backend
This question tests your ability to design a distributed, fault-tolerant transaction processing system for a digital storefront, focusing on data consistency and concurrency control.
System DesignOnsiteDistributed SystemsConcurrencyDatabase - DatabricksHardSoftware EngineerDesign a key-value store
This question evaluates understanding of durable storage and crash-consistency, including on-disk data layout, filesystem durability semantics, concurrency control, and performance trade-offs for single-node embeddable key–value engines.
System DesignOnsite - 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 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 - 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 - 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 - 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 - DoorDashMediumSoftware EngineerDesign Food Ratings and Driver Payouts
This question evaluates system design competencies such as API design, data modeling and storage selection for aggregated 5-point ratings, handling user-generated posts and likes, service decomposition, consistency trade-offs, scalability, and designing a monthly batch payout pipeline for driver earnings.
System DesignOnsite - DoorDashMediumSoftware EngineerDesign Food-Item Reviews, Ratings, and Mutable Vote Counts
Design item reviews and votes with purchase eligibility, unique reviews, rating aggregates, reliable counters, pagination, and recoverable caching.
System DesignOnsite - DoorDashHardSoftware EngineerDesign a 3-day donation platform
This question evaluates competency in designing scalable, highly available payment-enabled distributed systems, including skills in traffic spike handling, idempotency and reconciliation, real-time totals and leaderboards, latency and throughput planning, and compliance/privacy considerations.
System DesignOnsite - DoorDashMediumSoftware EngineerDesign a Donation Service with Reliable Payment and Payout Tracking
Design donation collection and charity payouts with a PSP, idempotent state transitions, durable ledger records, asynchronous provider events, and reconciliation.
System DesignOnsite
Databricks
Decagon
Discord
Disney
DoorDash