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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 38 results
- Akuna CapitalEasySoftware EngineerDesign user communication functions
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 user communication functions states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
System DesignOnline Assessment - Akuna CapitalHardSoftware EngineerFix and harden an object pool
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 Fix and harden an object pool states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
System DesignOnline Assessment - Akuna CapitalMediumSoftware EngineerImplement a two-user communications handler
This question evaluates skills in stateful resource management, API and abstraction design, custom exception handling, and input validation for enforcing a single-active connection between two users.
System DesignOnline Assessment - CircleHardSoftware EngineerDesign banking payment scheduling 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 banking payment scheduling system states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
System DesignOnline Assessment - CircleHardSoftware EngineerDesign flight-price search service
Design flight-price search 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 DesignOnline Assessment - CircleHardSoftware EngineerDesign in-memory DB with TTL and backup
A Circle software-engineer take-home: design a versioned in-memory key→(field→value) database with per-field TTL, append-only history and delete tombstones, lexicographically ordered scan and scanPrefix (correct even with special characters), and snapshot backup/restore counters. It exercises data modeling, time-travel visibility semantics, ordered indexing, garbage collection, and per-operation complexity trade-offs.
System DesignOnline Assessment - CircleMediumSoftware EngineerTrace and reduce redundant curl requests
A practical curl interview question on tracing and reducing redundant HTTP requests: instrumenting a curl-based client, finding duplicate calls, and cutting request volume. Includes a full worked solution.
System DesignOnline Assessment - CoinbaseHardSoftware EngineerDesign a bank account ledger
A complete take-home system-design walkthrough for a bank account ledger service: APIs and data model, an immutable double-entry ledger for auditability, ACID single-account updates and atomic multi-account transfers, idempotency and exactly-once effects, concurrency control, real-time/as-of/historical balance reads, monthly statements, reconciliation with external payment rails, limits, fraud and dispute handling, plus sharding, replicas, recovery, and monitoring strategies for scale.
System DesignOnline Assessment - CoinbaseMediumSoftware EngineerDesign cloud storage system
Design cloud storage system 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 DesignOnline Assessment - CoinbaseHardSoftware EngineerDesign scheduled payments and cancellation
A Coinbase software-engineering take-home: design a scheduled payments service that creates, lists, updates, executes, and cancels future-dated one-time and recurring transfers with exactly-once ledger correctness. It tests distributed-systems architecture, idempotent REST/gRPC API design, data modeling, concurrency control, DST handling, retries/backoff, outage backfill, and observability. The model answer pins correctness on a single-writer state machine plus an idempotent ledger.
System DesignOnline Assessment - Da Vinci TradingHardSoftware EngineerDesign an in-memory order matching engine
Matching engine design guide for an in-memory order book. Covers price-time priority, limit and market orders, matching rules, data-structure choices, edge cases, and how to explain tradeoffs in a system design interview.
System DesignOnline Assessment - DisneyMediumData EngineerDesign a clickstream ingestion and aggregation pipeline for billions of events per day
Design an end-to-end clickstream pipeline that ingests roughly one billion telemetry events per day from web, mobile, and TV clients and serves both near-real-time dashboards and accurate finalized daily aggregates without lagging. The question covers staged architecture and back-of-envelope sizing, a durable partitioned log for back-pressure, event-time windowing with watermarks and allowed lateness, late-arriving data and the provisional-to-finalized lifecycle, exactly-once deduplication in Flink versus Spark Structured Streaming, autoscaling on consumer lag, hot-partition key skew, high-cardinality DAU/MAU with HyperLogLog, and reprocessing after a logic bug. A common Disney data engineer online assessment system design question.
System DesignOnline Assessment - DoorDashMediumSoftware EngineerDesign a multi-channel notification system
This System Design question evaluates distributed-systems and API-design skills—scalability, reliable fanout, multi-channel integration, delivery guarantees (retries, idempotency, deduplication), rate-limiting, subscription/preferences modeling, and observability.
System DesignOnline Assessment - HubSpotMediumSoftware EngineerSchedule and execute future payments
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 Schedule and execute future payments states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
System DesignOnline Assessment - IBMHardSoftware EngineerDesign a multithreaded CPU 1D convolution
An IBM software-engineer take-home that asks you to design and implement a multithreaded CPU version of valid 1D convolution across three regimes: a tiny kernel (K=3), a kernel as long as the input (K=N, a single dot product), and a 100-thread cap. It evaluates parallel decomposition, scheduling, cache locality, false-sharing avoidance, SIMD vectorization, and reduction/synchronization choices.
System DesignOnline Assessment - InstacartMediumBackend EngineerDesign Idempotent Due-Date and Hold Notifications
Design idempotent library notifications for upcoming and current due dates plus FIFO hold availability. Use stable business-event identities, transactional scheduling, atomic recipient claims, state rechecks, retries, reconciliation, and clear frontend distinctions among holds, offers, and checkouts.
System DesignOnline Assessment - InstacartMediumSoftware EngineerDesign Idempotent In-App Availability and Due-Date Notifications
Design asynchronous in-app availability alerts and due-date reminders with Celery, Redis, durable idempotency, versioned schedules, and crash recovery.
System DesignOnline Assessment - InstacartHardSoftware EngineerDesign cloud storage with quotas and compression
This question evaluates a candidate's ability to design a multi-tenant cloud storage system, testing competencies in API design, quota accounting, compression strategies, distributed storage architecture (partitioning, replication/erasure coding), consistency models, security, versioning, and observability.
System DesignOnline Assessment - J.P. MorganEasySoftware EngineerImprove shopping cart latency and stock notifications
This question evaluates a candidate's ability to design scalable, low-latency e-commerce architectures and real-time notification mechanisms while reasoning about data consistency, concurrency control, and correctness under high traffic (including concerns like avoiding oversells).
System DesignOnline Assessment - KneronMediumSoftware EngineerOptimize machines for distributed merging cost
Optimize machines for distributed merging cost 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 DesignOnline Assessment - MathWorksMediumSoftware EngineerDesign a multi-tenant course purchase and delivery system
This question tests the ability to design a scalable multi-tenant architecture that manages course content, user entitlements, and purchase workflows across different organizational silos.
System DesignOnline AssessmentMulti-tenancyAPI DesignScalability - MetaHardSoftware EngineerDesign a basic bank system API
This question evaluates a candidate's ability to design and implement an in-memory banking API, focusing on data modeling, API semantics, invariants (such as monotonic timestamps and non-negative balances), idempotency, and basic concurrency control.
System DesignOnline Assessment - MetaMediumSoftware EngineerDesign a fitness tracking app
This problem tests your ability to design a scalable backend for a fitness tracking application, focusing on high-frequency sensor data ingestion, geospatial route storage, and efficient retrieval of historical user activities.
System DesignOnline AssessmentScalabilityGeospatialNoSQL - MetaHardSoftware EngineerDesign an in-memory cloud storage system
This question tests your ability to design a high-performance, in-memory distributed metadata store that supports hierarchical file structures, quota management, and efficient retrieval of top-k largest files.
System DesignOnline AssessmentData StructuresConcurrencyTrie - MetaHardSoftware EngineerMerge customers and preserve history
A 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.
System DesignOnline Assessment - MicrosoftMediumSoftware EngineerDesign a replicated key-value store with quorums
This question evaluates understanding of replication, quorum protocols, data partitioning, consistency models, failure detection and recovery, and conflict resolution in distributed key–value stores.
System DesignOnline Assessment - MicrosoftMediumSoftware EngineerDesign device telemetry pipeline for real-time and batch
This question evaluates a candidate's competency in distributed systems architecture, data engineering, and operational trade-offs involved in designing telemetry pipelines that support both near-real-time and batch analytics.
System DesignOnline Assessment - MicrosoftMediumSoftware EngineerDesign streaming error-log counting with moving average
This question evaluates understanding of real-time stream processing concepts such as event filtering, stateful per-service counting, sliding-window moving averages, late-event handling, scalability, and fault-tolerant state management for monitoring and alerting.
System DesignOnline Assessment - NVIDIAHardSoftware EngineerBuild a Jenkins CI for graphics tests
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 Build a Jenkins CI for graphics tests states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
System DesignOnline Assessment - NVIDIAHardSoftware EngineerDesign a Dockerized GPU test pipeline
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 a Dockerized GPU test pipeline states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
System DesignOnline Assessment
Akuna Capital
Circle
Coinbase
Disney
DoorDash
HubSpot
IBM
Instacart
J.P. Morgan
MathWorks
Meta
Microsoft
NVIDIA