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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 271–300 of 1311 results
- Capital OneMediumData EngineerEvaluate credit-limit increase profitability
This question evaluates a data engineer's competency in business analytics, unit-economics P&L modeling, risk-versus-revenue trade-off analysis, and experiment-driven evaluation of credit product changes.
System DesignTechnical Screen - Capital OneMediumMachine Learning EngineerValidate virtual credit card transactions from encoded IDs
This question evaluates understanding of virtual credit card product trade-offs and the ability to design data models and deterministic validation logic for encoded transaction attributes, testing competencies in payment systems, data encoding/decoding, and rule-based validation.
System DesignOnsite - CarvanaEasySoftware EngineerDesign an Attendance Payroll Service
This question evaluates system design and backend engineering skills, including API design, data modeling for time-series attendance, payroll computation logic, consistency guarantees, integration/synchronization with external sources, and strategies for handling high-volume, bursty traffic.
System DesignOnsite - CerebrasHardSoftware EngineerDesign a Multi-Channel Message Queue
This question evaluates understanding of data modeling for multi-tag messages, set-based subscription semantics, scalable system design, and algorithmic complexity for operations such as enqueue, dequeue, subscribe/unsubscribe, and intersection queries.
System DesignTechnical Screen - Charta HealthMediumSoftware EngineerGenerate Consistent Outputs for Similar Inputs
Design a semantic caching and computation deduplication system that identifies similar inputs, prevents duplicate expensive processing under concurrent load, and maintains consistent, versioned outputs.
System DesignOnsiteDistributed SystemsCachingVector Search - Chicago Trading CompanyMediumSoftware EngineerDesign a Pre-Trade Risk Check for an Electronic Order Path
This question tests the ability to design a high-throughput, low-latency risk engine capable of atomic exposure validation before orders reach an exchange, while balancing concurrency and strict fault tolerance.
System DesignOnsiteLow LatencyConcurrencyRisk Management - ChimeEasySoftware EngineerDesign load balancing, caching, and idempotent APIs
This question evaluates a candidate's competency in designing scalable, reliable backend architectures, specifically focusing on load balancing strategies, multi-layer caching, and idempotent API design.
System DesignTechnical Screen - ChimeHardSoftware EngineerDesign mobile check deposit system
This question evaluates a candidate's ability to design end-to-end, production-grade mobile check deposit systems, assessing competencies in system architecture, distributed systems, security and fraud prevention, regulatory compliance (Reg CC, Check 21), data durability, and operational observability.
System DesignOnsite - 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 - CitadelMediumSoftware EngineerDesign Inventory Availability and Order Placement
Design e-commerce inventory availability and order reservation without overselling under concurrent requests. Define on-hand, reserved, and available invariants; atomic multi-item placement; idempotent retries; expiration; and optimistic versus pessimistic control for hot SKUs.
System DesignTechnical Screen - CitadelMediumSoftware EngineerDesign a Course Registration System
Design a course registration system with relational models and APIs for enrollment, dropping, schedules, waitlists, and course browsing. The solution explains transactional capacity protection, idempotent retries, re-enrollment without duplicate rows, FIFO promotion, outbox notifications, and tests for final-seat races.
System DesignOnsite - CitadelMediumSoftware EngineerDesign a Low-Latency Metrics and Alerting Platform
Design a high-throughput, multi-tenant metrics ingestion and alerting engine capable of triggering critical alerts within two seconds. The question evaluates your knowledge of streaming architectures, time-series storage, cardinality management, and fault-tolerant notification delivery.
System DesignOnsiteTime SeriesDistributed SystemsStreaming - CitadelHardSoftware EngineerDesign a low-latency trading platform
This question tests the ability to architect a high-throughput, sub-millisecond trading system while balancing strict deterministic latency requirements with necessary safety checks.
System DesignOnsiteHFTLow-LatencyConcurrency - CitadelHardSoftware EngineerDesign a low-latency trading system
This question evaluates expertise in designing low-latency, high-determinism electronic trading systems, covering order matching, market data ingestion and publish, partitioning/sharding, persistence for auditability, idempotency, pre-trade risk controls, and operational reliability.
System DesignTechnical Screen - CitadelMediumSoftware EngineerDesign alerting for application-to-exchange mappings
This question evaluates understanding of real-time stream processing, alerting policy design, and distributed state coordination for application-to-exchange mappings, testing competencies in scalability, correctness under partitioning and duplication, and efficient aggregation of high-volume event streams.
System DesignOnsite - CitadelMediumSoftware EngineerDesign an Authenticated Online Shopping Service
Design an authenticated online shopping service with secure signup and login, user-owned carts, product browsing, and retry-safe order creation. The solution covers password hashing, session rotation, CSRF defenses, resource-level authorization, idempotency keys, immutable order snapshots, recovery tokens, and horizontal-access tests.
System DesignOnsite - CitadelHardSoftware EngineerDiscuss queues, NoSQL, and concurrency
This question evaluates understanding of distributed messaging systems, delivery semantics, push versus pull consumption models, NoSQL versus relational storage trade-offs, and concurrency control including deadlock concepts.
System DesignTechnical Screen - CitiMediumSoftware EngineerExplain OS and networking basics
This question evaluates a candidate's understanding of operating system and networking fundamentals, covering processes, threads and context switching, concurrency versus parallelism, TCP/UDP and flow versus congestion control, and the end-to-end web request and browser rendering pipeline.
System DesignOnsite - ClickupMediumSoftware EngineerDesign weekly comment digest
This question evaluates understanding of scalable system architecture, integration with external ML services, handling rate limits, reliable scheduling and delivery, data modeling for aggregation and deduplication, and fault-tolerant ranking under load.
System DesignOnsite - CloudKitchensMediumSoftware EngineerDesign real-time kitchen order fulfillment system
This question evaluates a candidate's competency in designing real-time backend systems, emphasizing concurrency control, stateful resource allocation, time-sensitive freshness constraints, efficient eviction policies, and action logging.
System DesignOnsite - CloudflareMediumSoftware EngineerDesign an encrypted log collection system
This question tests the ability to design a distributed, high-throughput ingestion pipeline that ensures log confidentiality and integrity using encryption at rest and in transit.
System DesignOnsiteSecurityDistributed SystemsEncryption - Cockroach LabsMediumSoftware EngineerPresent and Defend an End-to-End Project You Owned: Architecture, Choices, Challenges
A choose-your-own system design round: present a core project you owned end to end at a previous job, then defend its architecture, technology choices and hardest challenges under detailed probing. Tests depth of ownership, trade-off reasoning and the ability to move from a diagram to concrete mechanisms.
System DesignOnsite - CohereMediumSoftware EngineerAnswer Enterprise Questions Across Internal and External Sources
Design enterprise AI question answering across internal and external sources with permission-aware retrieval, entity mapping, evidence-grounded synthesis, and freshness controls.
System DesignTechnical Screen - CohereMediumFrontend EngineerDesign Real-Time Comments with Optimistic Updates
Design optimistic real-time comments with temporary identities, idempotent posting, response/event reconciliation, visible failure states, and durable history.
System DesignOther - CohereMediumFrontend EngineerDesign a Real-Time Comment System Front End With Optimistic Updates
Front-end system design for a real-time comment feed, centered on optimistic updates: a new comment is appended to the list before the backend confirms it, so the user can keep typing. It tests client state modeling, reconciliation with live echoes, failure and retry handling, ordering, reconnection and rendering performance.
System DesignOnsite - CoinbaseHardSoftware EngineerDesign Crypto Order Routing
This question evaluates a candidate's ability to architect distributed, low-latency, and fault-tolerant order-placement and routing systems for cryptocurrency trading, covering consistency guarantees, external integration with heterogeneous venue protocols, fund reservation, execution reconciliation, and auditability.
System DesignOnsite - CoinbaseHardFrontend EngineerDesign Frontend Architecture for Trading UI
This question evaluates competency in frontend architecture for real-time trading UIs, covering state management, rendering strategies, real-time data flow, performance, reliability, security, testing, and observability.
System DesignOnsite
Capital One
Cerebras
Chime
Circle
Citadel
Citi
Cloudflare
Cohere
Coinbase