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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 631–660 of 721 results
- SnapchatMediumSoftware EngineerDesign a device owner lookup service
This question tests the ability to design a distributed system for tracking the mapping between ephemeral devices and their currently signed-in users, focusing on handling event concurrency and high-throughput read/write operations.
System DesignOnsiteDistributed SystemsConcurrencyCaching - SnapchatMediumSoftware EngineerDesign a metrics collection and alerting system
This question evaluates system design competencies such as scalable time-series data modeling, ingestion and storage architecture, query latency versus retention trade-offs, and alert evaluation logic within the System Design domain.
System DesignOnsite - SnapchatMediumMachine Learning EngineerDesign a search-to-ads ranking pipeline
This question tests the ability to design a high-throughput, low-latency ranking system that balances user experience with monetization goals through multi-stage retrieval and bidding mechanics.
System DesignOnsiteRankingRecommendation-SystemsAd-Tech - SnapchatHardSoftware EngineerDesign a streaming ads system
This question evaluates a candidate's competency in designing low-latency, scalable, and privacy-compliant ad-insertion platforms, encompassing distributed systems, real-time bidding integration, ad format and measurement standards, content and identity signal processing, pacing/frequency control, and multi-region fault tolerance.
System DesignOnsite - SnapchatMediumSoftware EngineerDesign a swipeable video feed backend
This question evaluates system-design competence for building scalable, low-latency backend services that handle feed vending, pagination, personalized ranking, caching, storage, and content eligibility; it is categorized under System Design and tests practical application of distributed systems and backend data engineering principles.
System DesignOnsite - SnapchatHardSoftware EngineerDesign product co-occurrence analytics API
This question evaluates design skills for RESTful APIs and backend systems, covering API schema and versioning, authentication and rate limiting, caching and cache invalidation, storage models, precomputation pipelines, consistency and staleness bounds, monitoring, and operational concerns.
System DesignOnsite - SnapchatMediumSoftware EngineerDesign real-time ad impression and spend tracking
This question tests the ability to design a high-throughput, fault-tolerant system capable of tracking massive volumes of ad impression events and calculating real-time budget spending.
System DesignOnsiteDistributed SystemsCachingHigh Throughput - SnapchatHardSoftware EngineerDesign ride-hailing and price alert systems
This question evaluates a candidate's competency in large-scale system design, including distributed architecture, real-time data processing, geo-spatial indexing and low-latency matching for ride-hailing, plus scalable ingestion, time-series storage, rule evaluation, and reliable notification pipelines for price-tracking, within the System Design domain. It is commonly asked to assess architectural trade-offs around scalability, consistency, availability, fault tolerance and operational concerns, testing practical application of architectural patterns alongside conceptual understanding of data modeling and real-time constraints.
System DesignOnsite - SnowflakeMediumSoftware EngineerDesign a Photo Album Backend: Upload Consistency, Deduplication and Scaling
A backend system design prompt for a photo album service where users upload photos and organize them into albums. It probes keeping a metadata database and blob storage consistent on upload, showing new photos instantly despite processing lag, blocking duplicate uploads, and when a relational database stops scaling.
System DesignOnsite - SnowflakeHardSoftware EngineerDesign a Reliable Job Scheduler
This problem tests the ability to design a distributed, fault-tolerant job scheduler capable of handling task persistence, concurrency, and strict timing requirements at scale.
System DesignOnsiteDistributed SystemsConcurrencyFault Tolerance - SnowflakeHardSoftware EngineerDesign a concurrent web crawler
This problem evaluates your ability to design a distributed, concurrent web crawling architecture that balances high throughput with politeness policies, concurrency control, and robust state management.
System DesignOnsiteConcurrencyDistributed SystemsCaching - SnowflakeEasySoftware EngineerDesign a disk-backed KV store under contention
This problem tests the ability to design a persistent key-value store that balances disk I/O, memory caching, and thread safety under high concurrency.
System DesignOnsiteConcurrencyStorage EnginesLSM Trees - SnowflakeHardSoftware EngineerDesign cache for DAG-based query views
This question evaluates a candidate's understanding of caching, consistency, versioning, eviction, and update propagation in DAG-based materialized views, testing competencies in distributed systems, data engineering, and storage-hierarchy design.
System DesignOnsite - SnowflakeHardSoftware EngineerDesign multi-core service startup scheduler
This question evaluates scheduling and resource-management skills, including DAG dependency handling, concurrency bounding, timeout/retry strategies, observability, and correctness reasoning for service startup orchestration.
System DesignOnsite - SoFiHardSoftware EngineerDesign a Random Number Generation API
Design a Random Number Generation 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 - SoFiHardSoftware EngineerDesign a Real-Time Suggestions Service
Design a Real-Time Suggestions 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 DesignOnsite - SotiMediumSoftware EngineerDesign an IP blacklist API
This question evaluates API and backend system design skills for network security and distributed caching, encompassing data modeling for exact IPs and CIDR ranges, cache architecture and invalidation, consistency and failure handling, scaling, and observability.
System DesignOnsite - SpeakHardSoftware EngineerDesign scenario-based speaking feature
This question evaluates system-design competency in building scalable, real-time, multilingual audio-driven learning features, including product modeling, session orchestration, audio pipelines (ASR/TTS), personalization, localization, telemetry, and privacy/security considerations.
System DesignOnsite - SpeakHardSoftware EngineerDesign speaking scenarios and auth/profile API
This question evaluates a candidate's ability to design scalable, real-time speaking-practice features and a minimal authentication/profile API, encompassing system architecture, service decomposition, data modeling, ASR/LLM integration, personalization, security and privacy, and operational concerns like scaling and observability.
System DesignOnsite - SpotifyMediumBackend EngineerDesign a Public Upload and Hosting Service for Playlist Cover Images
A Spotify system design question: design a service that lets users upload, replace and remove a public cover image for their playlists, served to the app and to third-party embeds. Follow-ups cover how an auditor would review image changes and how upload and processing failures are handled.
System DesignOnsite - Sprinter HealthMediumSoftware EngineerDesign a scalable game app store
This question evaluates a candidate's ability to design a scalable backend system, covering competencies in system architecture, data modeling, distributed services, media asset delivery, secure transactional flows, and operational trade-offs around scalability, availability, and consistency.
System DesignOnsite - StripeMediumSoftware EngineerDesign a Count-Metrics Monitoring Platform
Design a scalable count-metrics monitoring and alerting platform capable of tracking real-time event counts and rates, grouping by dimensional labels, handling duplicate/late events, and enforcing cardinality limits.
System DesignOnsiteDistributed SystemsObservabilityStream Processing - StripeHardSoftware EngineerDesign a Distributed Metrics Counter
This question tests the ability to architect a highly available, scalable system for ingesting and aggregating high-throughput telemetry data while managing trade-offs between consistency and performance.
System DesignOnsiteDistributed SystemsMetricsScalability - StripeMediumSoftware EngineerDesign a Merchant Ledger Service
This question tests your ability to design a distributed ledger system that ensures high transactional integrity, strict consistency for financial balances, and reliable idempotency in a high-concurrency environment.
System DesignOnsiteDistributed SystemsDatabase DesignConsistency - StripeMediumSoftware EngineerDesign a Superhero Dispatch System
This question evaluates a candidate's ability to design reliable, distributed backend systems with emphasis on transactional correctness, concurrency control for single-winner acceptance races, geo-spatial querying for proximity matching, eventing/notification pipelines, and operational observability for mission-critical dispatch.
System DesignOnsite - StripeHardSoftware EngineerDesign ledger and bikemap integration
This question evaluates competency in designing strongly consistent financial ledgers and integrating an external routing service, testing data modeling, distributed transactions, linearizability and idempotency, scalability, security, API design, and observability in the System Design domain.
System DesignOnsite - StubHubMediumSoftware EngineerDesign Event Email System
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 Event Email System states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
System DesignOnsite - StubHubMediumSoftware EngineerDesign Internal Chat and Re-engagement Emails
This question evaluates a candidate's competency in designing scalable, real-time messaging systems and re-engagement workflows, covering distributed systems concepts such as WebSocket-based bidirectional communication, presence, cross-server message routing, message persistence, APIs, storage trade-offs, inactivity detection, and email-triggering workflows. Commonly asked in the System Design category, it tests high-level architectural reasoning and practical application of scalability, reliability, and failure-handling trade-offs when integrating persistent WebSocket connections, cross-server routing, and background email jobs in a distributed platform.
System DesignOnsite - StubHubMediumSoftware EngineerDesign a Global Marketing Email Platform
This problem tests your ability to design a high-throughput, fault-tolerant email delivery system that handles scheduling across time zones, manages email templates, and provides basic analytics.
System DesignOnsiteScalabilityDistributed SystemsMessaging - TeslaHardSoftware EngineerDesign a Distributed Blob Storage System for Build Artifacts
Design a distributed storage system for build artifacts, similar to a distributed NoSQL database but storing opaque blobs with looser ACID requirements. It tests separating immutable data from consistent metadata, upload atomicity, replication and repair, handling download fan-out, and safe retention and garbage collection.
System DesignOnsite
Snapchat
Snowflake
SoFi
Spotify
Stripe
StubHub
Tesla