practice a little every day, paws crossed ♡
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 1–30 of 517 results
- Abnormal SecurityHardSoftware EngineerDesign a scalable photo deduplication service
Design a scalable photo deduplication service 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 - AbridgeMediumSoftware EngineerDesign a Secure Medical Audio Pipeline
This problem tests your ability to design a secure, HIPAA-compliant audio processing pipeline that handles sensitive PHI (Protected Health Information) while ensuring scalability and reliability.
System DesignTechnical ScreenSecurityHIPAAAsynchronous Processing - AddeparMediumSoftware EngineerDesign a Multi-Region Event Ticketing System
This question tests the ability to design a highly concurrent distributed system that balances strong consistency for inventory management with high availability for a global, read-heavy user base.
System DesignTechnical ScreenDistributed SystemsConsistencyScalability - AdobeHardSoftware EngineerAnalyze end-to-end request latency
An Adobe software-engineer system-design screen on analyzing and optimizing end-to-end web request latency. The strong answer builds a client/network/server latency model, instruments both client (RUM) and server (OpenTelemetry, Server-Timing) with correlated traces, attributes frontend vs. backend time, investigates p95/p99 outliers, and ships layered optimizations behind SLO guardrails.
System DesignTechnical Screen - AdobeHardSoftware EngineerDesign distributed word count without MapReduce
This question evaluates a candidate's competency in designing scalable distributed systems and large-scale data processing pipelines, focusing on ingestion, partitioning/sharding, partial aggregation and merging, global top‑K computation, fault tolerance, idempotency, and storage/serving concerns.
System DesignTechnical Screen - AdyenHardSoftware EngineerDesign scalable LRU cache and backtracking API
Design scalable LRU cache and backtracking API 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 - AffirmMediumSoftware EngineerDesign Installment-Loan Payment Processing
Design installment-loan payment processing around a bank debit API available during one daily one-hour window. Unify manual and scheduled intents, prevent duplicate debits with durable idempotency and state transitions, reconcile unknown outcomes, apply accounting atomically, and notify through an outbox.
System DesignTechnical Screen - AirbnbHardSoftware EngineerDesign a fast host listing metrics page
This question evaluates backend system design and data engineering competencies, including scalable API design, time-range aggregation correctness (handling partial overlaps and state changes), data modeling and indexing, caching and precomputation, and performance validation.
System DesignTechnical Screen - AirbnbHardSoftware EngineerDesign a multi-channel notification system
This question tests the ability to design a distributed, multi-channel notification system capable of handling high throughput, varying latency requirements across channels (e.g., email, push, SMS), and ensuring reliable message delivery.
System DesignTechnical ScreenDistributed SystemsScalabilityMessage Queues - AirbnbHardSoftware EngineerDesign an Airbnb wallet with holds and payouts
This question evaluates a candidate's competency in designing financial transaction systems, covering double-entry append-only ledgers, holds/authorizations and captures, refunds and payouts, multi-currency FX conversion and rounding, idempotency, concurrency safety, and auditable reconciliation.
System DesignTechnical Screen - AirbnbMediumSoftware EngineerDesign and implement an Airbnb wallet
This question evaluates system design and object-oriented design skills focused on transactional accounting, escrow-based payment flows, idempotency, and robust error handling, plus the ability to produce a runnable in-memory implementation.
System DesignTechnical Screen - AirwallexMediumSoftware EngineerDesign a High-Demand Ticketing System
Design a ticketing system for high-demand events. Connect requirements and APIs to data modeling, consistency, scaling, failure recovery, observability, and the important design trade-offs.
System DesignTechnical Screen - AirwallexMediumSoftware EngineerDesign a Large-File Analysis Report System
Tests system design skills in architecting a secure, multi-tenant pipeline for large file ingestion and asynchronous batch analytics with resumable uploads and idempotent job processing.
System DesignTechnical ScreenObject StorageDistributed SystemsIdempotency - AirwallexMediumFrontend EngineerDesign a Reusable React Autocomplete Input: API, Portals, Debounce and Caching
Design a reusable autocomplete search input for a React application on top of an existing search API. The discussion covers the API contract with pagination and limits, the component and portal architecture, throttling versus debouncing, client-side result caching strategies, and the public props and exports.
System DesignTechnical Screen - Akuna CapitalHardSoftware EngineerDesign an order-matching engine
This question evaluates a candidate's ability to design a high-throughput, low-latency in-memory limit order-matching engine, testing competencies in data structure selection, algorithmic complexity, deterministic concurrency, API design, and handling domain-specific constraints such as self-trade prevention.
System DesignTechnical Screen - AlibabaMediumSoftware EngineerIdempotent Kafka Consumer: Duplicate Writes, Offset Commits and a Second Database
A backend design discussion on making a concurrent Kafka consumer idempotent: how to stop duplicate effects when the same message is processed twice, whether a duplicate write should throw or return the existing data, how offsets keep advancing, and how to keep a second database consistent when publishing fails.
System DesignTechnical Screen - AltruistHardSoftware EngineerDesign scalable rate limiter with token bucket
This question evaluates understanding of rate-limiting algorithms and scalability concepts, specifically comparing sliding-window and token-bucket approaches with attention to lazy refill, per-client state modeling, memory efficiency, concurrency, and extendability to distributed systems.
System DesignTechnical Screen - AmazonMediumSoftware EngineerAccept Notification Bursts With Low Latency
Design a high-throughput, low-latency notification ingestion and delivery service capable of absorbing sudden 10x traffic spikes while maintaining strict delivery SLOs and downstream rate limits.
System DesignTechnical ScreenDistributed SystemsMicroservicesMessage Queues - AmazonMediumSoftware EngineerArchitect an AI Chatbot for Enterprise Users
This question tests your ability to design a scalable, enterprise-grade AI chatbot system that handles high throughput, ensures data privacy, and integrates with existing business data stores.
System DesignTechnical ScreenRAGScalabilityAccess Control - AmazonMediumSoftware EngineerDesign Human Avoidance for Warehouse Robots
This problem evaluates your ability to design a real-time sensor-to-actuator pipeline for an autonomous robot, focusing on latency, sensor fusion, and safety-critical path adjustments.
System DesignTechnical ScreenRoboticsSensor FusionReal-time Systems - AmazonHardSoftware EngineerDesign VPC, IP plan, management, storage, SSO
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 VPC, IP plan, management, storage, SSO states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
System DesignTechnical Screen - AmazonMediumSoftware EngineerDesign a Kafka-Based File Watcher for Millions of Files
Design a Kafka file watcher for millions of files with source sharding, durable events, per-file ordering, missed-event reconciliation, and version-aware reads.
System DesignTechnical Screen - AmazonHardSoftware EngineerDesign a Library Management System (API and Schema)
This problem evaluates your ability to design a schema and API for a transactional library system, focusing on handling concurrent checkouts and maintaining data integrity in a read-heavy environment.
System DesignTechnical ScreenDatabase ModelingConcurrencyREST API - AmazonMediumSoftware EngineerDesign a Multi-Branch Library Lending System
This problem tests the ability to design a distributed inventory and reservation system, focusing on concurrency control, transaction integrity across branches, and fault-tolerant service communication.
System DesignTechnical ScreenConcurrencyDistributed SystemsInventory - AmazonMediumSoftware EngineerDesign a Perishable-Goods Inventory and Location Tracking System
This question tests the ability to design a distributed inventory system that handles high-frequency location updates and strict FIFO/expiry logic for perishable goods.
System DesignTechnical ScreenGeo-spatialScalabilityDatabase Modeling - AmazonEasySoftware EngineerDesign a Scalable News Feed
This problem evaluates your ability to design a feed generation architecture, specifically comparing push vs. pull models for users with varying follower counts.
System DesignTechnical ScreenCachingScalabilityDatabases - AmazonHardSoftware EngineerDesign a cloud database write path and recovery
This question tests the ability to architect a distributed database write path that decouples compute from storage, specifically focusing on how to maintain ACID properties during failures.
System DesignTechnical ScreenDistributed SystemsDatabasesDurability - AmazonHardSoftware EngineerDesign a keyboard and mouse input system
An Amazon software-engineer system-design screen: design a system that captures keyboard and mouse events and reconstructs exactly what the user typed. It tests low-latency event capture, total ordering across multiple devices, IME/composition and grapheme-safe text reconstruction, mouse selection and clipboard/undo-redo, plus durable persistence with deterministic crash-safe replay.
System DesignTechnical Screen - AmazonMediumSoftware EngineerDesign a large-scale temperature sensor system
This question tests your ability to design a high-throughput data ingestion pipeline and storage architecture for a fleet of IoT sensors, focusing on write-heavy scalability and time-series query performance.
System DesignTechnical ScreenTime-SeriesScalabilityDistributed Systems - AmazonHardSoftware EngineerDesign a log filtering and analytics service
An Amazon software engineer system design question: design a log filtering and analytics service that ingests high-volume application logs and supports attribute/substring filtering, error counts over a time window, and hourly histograms by pattern or ID. It tests ingestion API design, dual search + OLAP storage with hourly rollups, schema and indexing, late/duplicate-event handling, partitioning and retention, and correctness-vs-latency trade-offs with complexity analysis.
System DesignTechnical Screen
Abridge
Adobe
Affirm
Airbnb
Airwallex
Akuna Capital
Alibaba
Amazon