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Software Engineer 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 241–270 of 1189 results
- ByteDanceMediumSoftware EngineerEvaluate a Migration from MySQL to MongoDB
Evaluate whether a MySQL-backed service should migrate to MongoDB using its actual workload and correctness needs. Compare relational and document models, joins and transactions, then outline a dual-run migration, rollback plan, and measurements that would prove an improvement.
System DesignTechnical Screen - ByteDanceMediumSoftware EngineerModel Campaigns, Targeting, and Edit History for a Demand-Side Ad Platform
Model a demand-side ad platform with advertisers, campaigns, ad groups, ads, and creatives, including audience rules, edit history, and versioned publishing.
System DesignOnsite - ByteDanceMediumSoftware EngineerPrevent a Cache Stampede on a Hot Key
This question tests the ability to design robust cache-aside mechanisms to prevent database overload during cache expiration events for high-traffic keys.
System DesignTechnical ScreenCachingDistributed SystemsHigh Availability - ByteDanceMediumSoftware EngineerTrace and Debug Agent Tool-Call Failures
Design a distributed observability and tracing system to monitor, debug, and diagnose multi-step agent tool-call failures across retries and execution stages without leaking sensitive data.
System DesignTechnical ScreenDistributed TracingObservabilityAI Agents - C3 AIEasySoftware EngineerDesign a restaurant reservation system
This question evaluates skills in system architecture and engineering, including data modeling, API design, concurrency control to prevent double-booking, availability and scheduling logic, scalability under traffic spikes, and operational concerns like auditability and low-latency queries.
System DesignOnsite - Capital OneMediumSoftware EngineerCard Issuer Backend: Fast Purchase Approvals and a Secure PII Vault
Design the issuer-side platform that approves or declines card purchases in tens of milliseconds, settles them later, and stores cardholder identity data so a breach of any one service exposes as little as possible.
System DesignTechnical Screensystem-designpaymentslatency - Capital OneMediumSoftware EngineerDesign a Buy-Now-Pay-Later Checkout Backend: Latency and PII Storage
Design the backend of a buy-now-pay-later checkout financing service that approves or declines a purchase in real time against a shopper's revolving credit line, then go deep on latency budgeting for the decision and on securely storing borrowers' personal data.
System DesignTechnical Screensystem-designfintechconcurrency - Capital OneMediumSoftware EngineerDesign a Credit Card System: Authorization Latency and Sensitive Data Storage
A system design question that asks for the backend of a credit card system, then goes deep on what payment authorization latency is reasonable and how to achieve it, and on how to store cardholders' sensitive personal information. It tests transaction flow design, available-credit concurrency, latency budgeting, and data protection.
System DesignTechnical Screen - Capital OneMediumSoftware EngineerDesign a Credit Card System: Authorization, Fraud, Bureau Reports, Limit Increases
A system design question for a credit card platform covering customer login, real-time payment authorization with fraud checks, monthly credit bureau reporting, a spending overview, and instant credit limit increase decisions. It tests laying out entities, services and read and write paths before choosing deep dives.
System DesignTechnical Screen - Capital OneMediumSoftware EngineerDesign a highly reliable account balance system
This question evaluates a candidate's ability to architect a highly reliable transactional account-balance service, testing competencies in data modeling and storage choice, API design for idempotency, concurrency and consistency mechanisms, replication/failover, partitioning for scale, and auditability.
System DesignOnsite - Capital OneHardSoftware EngineerDesign a scalable banking system
This question evaluates system design skills focused on distributed systems architecture, transactional integrity, strong consistency models, security and authentication, external payment and ATM integrations, data modeling, API design, concurrency control, and operational monitoring for financial platforms.
System DesignOnsite - Capital OneMediumSoftware EngineerDesign an Enterprise Agent Platform with Guardrails and Latency Control
Design an enterprise agent platform with durable execution, deliberate workflow-versus-agent choices, enforceable tool guardrails, and a dependency-aware latency plan.
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
C3 AI
Capital One
Cerebras
Chime
Circle
Citadel