Topic
System Design interview questions
1311 System Design questions from 230 companies, with hints, runnable code and solution walkthroughs.
60 easy819 medium432 hard
System Design interview questions by the numbers
Last updated
Katkat has 1,311 System Design interview questions from 230 companies; the most come from OpenAI (8%), Meta (5%) and Amazon (4%). By difficulty: 5% easy, 62% medium and 33% hard. The most common round is Onsite (55%). Frequent concepts include System Design, Distributed Systems, Scalability and Caching.
Companies (230)
Difficulty
- Easy5% · 60
- Medium62% · 819
- Hard33% · 432
Interview rounds
- Onsite55% · 721
- Technical Screen39% · 517
- Online Assessment3% · 38
- Other2% · 21
- HR Screen1% · 13
Roles
- Software Engineer91% · 1189
- Machine Learning Engineer2% · 31
- Data Engineer2% · 26
- Backend Engineer2% · 25
- Frontend Engineer1% · 19
Frequent concepts
- System Design31% · 400
- Distributed Systems24% · 316
- Scalability15% · 196
- Caching7% · 95
- Concurrency7% · 91
- system-design6% · 83
Most mentioned in interview experiences
- 1.Design delivery driver payment system3 reports
- 2.Debug round-robin request router2 reports
- 3.Design a basic bank system API2 reports
- 4.Design a delivery cost system2 reports
- 5.Design a Distributed Key-Value Store for a Small Company's Internal Use2 reports
- 6.Design a Donation System for a Three-Day Fundraising Campaign2 reports
- 7.Design a file search module like UNIX find2 reports
- 8.Design a Food Review System for a Delivery App, Focused on the Database Schema2 reports
- 9.Design a Job Scheduler for ML Training and Batch Inference on a Shared Cluster2 reports
- 10.Design a Menu Item Review and Rating System for a Food-Delivery Platform2 reports
Counted from 393 candidate interview experiences on Katkat. How we collect and count
Showing 691–720 of 1311 results
Design batch and streaming ETL architecture 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.
MetaData EngineerSystem DesignOnsiteThis question tests the ability to design a high-throughput, real-time leaderboard system that balances strong consistency for rankings with the scalability required for a global user base.
MetaSoftware EngineerSystem DesignOnsiteA Meta software engineer system design technical screen: design the API and system-level input validation and error-handling strategy for a service that computes the top-k most frequent elements in a posted array. The merged answer covers the request/response contract with a worked example, payload and cardinality limits, layered validation across client, gateway and service, authentication, rate limiting, idempotency, timeouts and retries, the full 4xx/5xx error taxonomy with sample error responses, partial-failure modes, graceful degradation to approximate top-k with stated error bounds, defenses against compression bombs and poisoned payloads, observability, and a test and production monitoring plan.
MetaSoftware EngineerSystem DesignTechnical ScreenThis question evaluates the candidate's ability to design scalable, low‑latency real‑time messaging systems, focusing on high‑fanout delivery, approximate time ordering, moderation and rate‑limiting mechanisms, and replay of recent events.
MetaSoftware EngineerSystem DesignOnsiteThis question evaluates an engineer's ability to design globally distributed, highly scalable media storage and delivery systems, covering competencies in object storage and metadata modeling, CDN integration, replication and consistency strategies, security and access control, background processing, observability, quotas, and cost/performance trade-offs. It is commonly asked in system design interviews to assess reasoning about durability, availability, latency and cost trade-offs while requiring both high-level architectural thinking and practical implementation details; category: System Design; level of abstraction: combines conceptual architecture with practical application considerations.
MetaMachine Learning EngineerSystem DesignOnsiteDesign searchable status & geolocation services 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.
MetaSoftware EngineerSystem DesignOnsiteThis question evaluates relational data modeling and data engineering competencies for high-volume event analytics, including schema design, partitioning and clustering strategies, duplicate and late-arriving event handling, and normalization versus denormalization trade-offs.
MetaData EngineerSystem DesignTechnical ScreenA product architecture design problem: starting from a feed mock-up, design the client data flow and APIs for a social news feed on web and mobile. It tests UX flow analysis, the shape of the feed response object, cursor-based pagination, and edge cases across client types.
MetaSoftware EngineerSystem DesignOnsiteThis question evaluates a candidate's skills in system design, distributed systems, concurrency control, data modeling, and scalability, testing their ability to reason about correctness and performance under high contention and heavy traffic as well as trade-offs between consistency and availability.
MetaSoftware EngineerSystem DesignOnsiteThis question evaluates competency in metrics definition, causal experimentation, product analytics, and feed system behavior within the System Design and Data Engineering domain.
MetaData EngineerSystem DesignOnsiteDesign a high-scale gaming leaderboard service capable of real-time score updates, deterministic tie-breaking, friend-filtered leaderboards, and efficient "nearby competitor" queries under extreme write loads.
MetaSoftware EngineerSystem DesignOnsiteA Meta software-engineer system-design take-home: implement mergeCustomers(oldId, newId) for a payments/ledger platform, absorbing one customer into another while preserving every account's balance and immutable transaction history. Tests identity unification, ownership remap, conflict/duplicate resolution, top-N leaderboard maintenance, atomicity, concurrency, idempotency, and complexity analysis.
MetaSoftware EngineerSystem DesignOnline AssessmentTests your ability to design a horizontally scalable distributed rate limiter and caching layer, focusing on data partitioning, hot-key mitigation, failure modes, and consistency trade-offs.
MetaSoftware EngineerSystem DesignOnsiteThis question tests your ability to diagnose a sudden service outage on a single-node web server and your ability to propose architectural changes to prevent future single points of failure.
MetaSoftware EngineerSystem DesignTechnical ScreenPrepare for a read-heavy product pricing system design interview where prices update infrequently but launch-page reads must be low latency. The prompt focuses on versioned price records, caching, bulk reads, invalidation, rollback, and consistency after daily updates.
MicrosoftSoftware EngineerSystem DesignOnsiteThis question evaluates scalable system architecture and distributed systems competencies, specifically testing web crawler concepts such as URL discovery and deduplication, scheduling and prioritization, politeness-aware fetching, parsing and link extraction, storage of content and metadata, failure handling, and monitoring.
MicrosoftSoftware EngineerSystem DesignTechnical ScreenDesign product pages and trackable sharing links with anonymous-visitor limits, atomic every-Nth rewards, recoverable redemption, and engagement analytics.
MicrosoftSoftware EngineerSystem DesignOnsiteA system design exercise to build proximity search for a food-delivery app that finds restaurants within 10 km of a customer, followed by hand-coding the core lookup. It tests geospatial indexing, read and write paths, partitioning, handling dense areas, and turning a design into correct code.
MicrosoftSoftware EngineerSystem DesignOnsiteThis question evaluates a candidate's ability to design end-to-end re-engagement and reminder notification systems, assessing competencies in system architecture, data modeling, scheduling and delivery pipelines, reminder extraction from natural language, user preferences, rate limiting, metrics, privacy, reliability, and scalability.
MicrosoftSoftware EngineerSystem DesignOnsiteThis question tests the ability to design a scalable, low-latency LLM inference system, focusing on request handling, KV-cache optimization, and horizontal scaling strategies.
MicrosoftSoftware EngineerSystem DesignTechnical ScreenTests your ability to architect a highly available, horizontally scalable distributed key-value store, evaluating core concepts including consistent hashing, tunable quorum consistency, storage engine trade-offs, and failure recovery.
MicrosoftSoftware EngineerSystem DesignOnsiteDesign global one-to-one voice calls with device registration, signaling, accept/reject races, media negotiation, relay fallback, and mobile recovery.
MicrosoftSoftware EngineerSystem DesignOnsiteDesign a scalable incident ticket correlation and management system capable of handling high-volume alert storms, maintaining interval-based status history, and performing asynchronous, idempotent incident deduplication and linking.
MicrosoftSoftware EngineerSystem DesignOnsiteDesign a storage system that ingests a massive stream of log records into files and serves reads, including readers following files that are still being written. It probes partitioning, metadata for locating data across nodes, batching for write throughput, position-based live delivery, and the cost of long-lived reader connections at scale.
MicrosoftSoftware EngineerSystem DesignOnsiteDesign a system that dispatches compute payloads to lab machines that poll for work and shows on a central dashboard whether each payload is downloading, running, completed, crashed, or hung. It tests agent design, hang detection, crash and hang logs, authorized reboot and power cycle, reruns after interruption, and refreshable machine inventory.
MicrosoftSoftware EngineerSystem DesignOnsiteA system design exercise for a real-time bike-sharing service where riders find nearby bikes, reserve and unlock them, and end trips by locking. It tests gathering requirements first, choosing location reporting rates, keeping telemetry writes off the transactional database, and making reservations correct under contention.
MicrosoftSoftware EngineerSystem DesignOnsiteA senior-level system design prompt asking for a browser-based document editor where many people edit the same file at once, similar to Google Docs. It tests concurrency control for simultaneous edits, real-time sync, durable storage with version history, sharing permissions, and how the service scales and recovers from failures.
MicrosoftSoftware EngineerSystem DesignOtherA senior system design question about a role-based access control system with roles, permissions, scoped assignments and inheritance, plus a permission check on every protected request. It tests data modeling, fast check evaluation, caching with a bounded revocation delay, behavior on failure, and auditing of changes.
MicrosoftSoftware EngineerSystem DesignOnsiteThis question evaluates proficiency in designing secure, multi-tenant API systems with emphasis on authentication and authorization models, token lifecycle management, threat mitigation (such as replay attacks, token theft, and misuse), access control across tenants and tools, and scalability and reliability concerns.
MicrosoftSoftware EngineerSystem DesignOnsiteSystem design question about a shared proxy layer that lowers what microservices spend calling metered API endpoints. It tests placement choices, response caching, collapsing duplicate requests, batching, quotas and budgets, safe retries for writes, failure policies and per-service cost attribution.
MicrosoftSoftware EngineerSystem DesignOnsite