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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 1–30 of 721 results
- AdobeMediumSoftware EngineerDesign a Runtime Localization System
Design a runtime localization system for dozens of countries with locale and regional resolution, variables, plural rules, safe fallback, and offline-capable bundles. Address live copy updates, approvals, rollbacks, formatting, missing translations, cache behavior, and longer-text layout failures.
System DesignOnsite - AffirmEasySoftware EngineerDesign a Ticketmaster-like ticketing system
This question tests your ability to design a high-concurrency booking system, focusing on preventing double-bookings, managing seat holds, and ensuring system availability during high-traffic events.
System DesignOnsiteConcurrencyDistributed SystemsCaching - AffirmHardSoftware EngineerDesign an A/B Testing Platform
Design a high-scale, low-latency experimentation and A/B testing platform capable of deterministic user bucketing, high-throughput exposure and metric ingestion, and automated statistical reporting.
System DesignOnsitesystem-designdistributed-systemsdata-engineering - AirbnbMediumSoftware EngineerDesign a Reliable Scheduler for Payment Jobs
Tests candidate's ability to design a mission-critical, fault-tolerant job scheduler for payment processing, focusing on lease claiming, idempotency, race condition handling, and reconciliation.
System DesignOnsitesystem-designdistributed-systemspayments - AirbnbHardBackend EngineerDesign a Rental Marketplace Backend
This problem tests your ability to design a distributed, high-scale rental marketplace platform, focusing on concurrency control for bookings, efficient geo-spatial searching, and data consistency.
System DesignOnsiteDistributed SystemsConcurrencyGeo-spatial - AirbnbMediumSoftware EngineerDesign a booking system
This question tests the ability to design a distributed reservation system that handles high concurrency, prevents double-booking, and ensures data consistency at scale.
System DesignOnsiteConcurrencyDatabaseDistributed Systems - AirbnbHardSoftware EngineerDesign a group chat system
Airbnb's onsite system design round asks you to design the backend for a real-time group chat and messaging system: 1:1 and group conversations, near-real-time delivery, accurate unread counts, and full paginated history at roughly 1B messages a day and 5M concurrent connections. A complete answer covers the guarantees, APIs, data model and partitioning, write path and ordering, WebSocket fan-out and presence, offline delivery and multi-device sync, unread counts, membership changes, failure modes and observability. This walkthrough gives a corrected end-to-end reference answer for every part, including the trade-offs interviewers probe.
System DesignOnsite - AirbnbHardSoftware EngineerDesign a hot-listing waitlist API
Design a hot-listing waitlist 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 DesignOnsite - AirbnbHardSoftware EngineerDesign a real-time chat system with hot groups
This problem tests your ability to design a distributed, low-latency messaging system that handles massive fan-out and identify trending group activities.
System DesignOnsiteDistributed SystemsWebSocketsCaching - AirbnbHardSoftware EngineerDesign a scalable consumer feature
This question evaluates a candidate's ability to design large-scale recommendation systems, covering system architecture, real-time serving and offline pipelines, personalization and ML modeling (candidate generation and ranking), data modeling/feature stores, caching and storage, monitoring, experimentation, and privacy/compliance skills.
System DesignOnsite - AirbnbHardSoftware EngineerDesign an A/B Testing Platform
Design an A/B testing platform with deterministic assignment, versioned experiment configuration, exposure logging, outcome attribution, and trustworthy analysis. Separate the latency-sensitive serving path from asynchronous metrics, support gradual ramps and overlapping tests, and detect bias, event loss, skew, and sample-ratio mismatch.
System DesignOnsite - AirbnbHardSoftware EngineerDesign multi-currency pricing end-to-end
This question evaluates understanding of multi-currency pricing and payments, covering currency selection UX, storage versus presentation currency, exchange-rate sourcing and locking, rounding and localization, tax and fee modeling, caching and cross-channel consistency, and API and data-model design in a distributed marketplace.
System DesignOnsite - AirbnbHardSoftware EngineerDesign rental watchlist and notification system
This question evaluates system architecture and scalability competencies, including data modeling for date-range watchlists, event-driven notification pipelines, time-zone and DST handling, consistency and concurrency semantics, idempotency, sharding/caching strategies, and privacy/analytics considerations.
System DesignOnsite - AirbnbHardSoftware EngineerDesign scalable notification system
Airbnb's onsite system design round asks you to design a notification system that delivers email, SMS, and push messages to millions of guests, hosts, and employees, supporting both event-triggered sends and large batch campaigns. A complete answer covers requirements and scale math, architecture and data flow for both modes, the data model and API, templating, user preferences and compliance, prioritization, deduplication and idempotency, retries and failover, scaling and backpressure, observability, and cost. This walkthrough gives a corrected end-to-end reference answer for every part, including the trade-offs interviewers probe.
System DesignOnsite - AirtableHardSoftware EngineerDesign JSON serialization for circular references
This question evaluates understanding of deterministic, cross-language JSON serialization and deserialization for object graphs with cycles, including concepts such as cycle detection, stable object identifiers, preservation of shared subobjects, traversal-order determinism, input validation/security, and time/space complexity.
System DesignOnsite - AirtableMediumSoftware EngineerDesign a scalable search service with sharding
This question tests the ability to design a distributed search architecture capable of handling high-throughput indexing and low-latency queries across a massive dataset.
System DesignOnsiteDistributed SystemsSearch IndexingSharding - AirtableMediumSoftware EngineerDesign an async API with idempotency
This question tests the ability to design a distributed asynchronous processing system that ensures idempotency, data consistency, and reliable task execution under high concurrency.
System DesignOnsiteAPIIdempotencyAsync - AmazonMediumSoftware EngineerDesign Faceted Product Search at Large Scale
Design a scalable e-commerce product search engine supporting full-text query matching, multi-attribute filtering, dynamic facet aggregations, and near real-time updates for volatile data like price and inventory.
System DesignOnsiteSearchDistributed SystemsInformation Retrieval - AmazonMediumSoftware EngineerDesign Music Search, Playlists, and Playback Controls
This problem tests the ability to design a scalable music streaming architecture, focusing on data modeling for search indices, conflict resolution in distributed state management, and robust API design for real-time playback control.
System DesignOnsiteDistributed SystemsAPIsConcurrency - AmazonHardSoftware EngineerDesign Thread-Safe Tagging and Bookstore Systems
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 Thread-Safe Tagging and Bookstore Systems states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
System DesignOnsite - AmazonHardSoftware EngineerDesign a Core Dump Collection and Analysis System
This problem tests the ability to design a distributed, scalable ingestion and analysis pipeline for massive binary crash files while maintaining system performance and data availability.
System DesignOnsiteDistributed SystemsScalabilityStorage - AmazonMediumSoftware EngineerDesign a Distributed Cron Job Scheduler
Design a fault-tolerant, horizontally scalable distributed cron scheduler capable of triggering millions of recurring tasks with at-least-once delivery semantics and deterministic run coordination.
System DesignOnsiteDistributed SystemsSchedulingFault Tolerance - AmazonHardSoftware EngineerDesign a Distributed Job Scheduler with Run Logs and Exactly-Once Execution
Design a highly available distributed job scheduler that handles one-time and recurring jobs, collects execution logs, and rigorously addresses the practical boundaries of exactly-once execution.
System DesignOnsitesystem-designdistributed-systemsconcurrency - AmazonHardSoftware EngineerDesign a High-Availability Load Balancer
This problem tests the ability to architect a highly available, scalable Layer 7 load balancer, focusing on fault tolerance, traffic distribution strategies, and system reliability.
System DesignOnsiteDistributed SystemsLoad BalancingHigh Availability - AmazonMediumSoftware EngineerDesign a Low-Latency Ad Serving Backend With Targeting, Budgets and Tracking
An Amazon system design question: design an ad server that selects and returns an ad for each page request within a tight latency budget. It covers targeting and candidate retrieval, ranking and auctions, budget enforcement and pacing, impression and click tracking, and failure handling.
System DesignOnsite - AmazonMediumSoftware EngineerDesign a Multi-Provider Financial Dashboard
Design a financial dashboard that reconciles balances, securities, cryptocurrency, prices, and derived metrics from unreliable external providers. Explain freshness, historical reproducibility, permissions, corrections, outages, and how users can recognize partial or inconsistent data.
System DesignOnsite - AmazonMediumSoftware EngineerDesign a Product Image Upload Pipeline for Sellers
Design an asynchronous, distributed image processing and delivery pipeline for an e-commerce seller portal, focusing on direct-to-cloud uploads, state management, moderation workflows, and resilient global caching.
System DesignOnsitesystem-designdistributed-systemsevent-driven - AmazonMediumSoftware EngineerDesign a Ride-Hailing Matching System
This question evaluates competence in large-scale real-time system design, covering high-throughput ingestion and burst absorption, stream deduplication, geospatial indexing, and low-latency matching and caching for ride-hail workflows.
System DesignOnsite - AmazonMediumSoftware EngineerDesign a Scalable Metrics Monitoring System
Design a high-throughput time-series metrics monitoring and alerting platform similar to Amazon CloudWatch, focusing on series identity, cardinality controls, and low-latency aggregations.
System DesignOnsitesystem-designtime-seriesmonitoring - AmazonMediumSoftware EngineerDesign a Scalable and Polite Web Crawler
This question tests the ability to design a distributed, fault-tolerant system that balances high-throughput data collection with ethical crawling constraints and resource efficiency.
System DesignOnsiteDistributed SystemsQueueingData Pipelines
Adobe
Affirm
Airbnb
Airtable
Amazon