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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 781–810 of 1311 results

  • NetflixMediumSoftware Engineer
    Design Ad Frequency and Order Tracking

    This question tests the ability to design a high-throughput, low-latency distributed counter service for frequency capping and an accurate tracking system for ad order delivery.

    System DesignOnsiteScalabilityDistributed SystemsCaching
  • NetflixMediumSoftware Engineer
    Design Netflix viewport deduplication

    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 Netflix viewport deduplication states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    System DesignTechnical Screen
  • NetflixHardSoftware Engineer
    Design Publisher Configuration Rules

    This question evaluates system design skills focused on configuration management and rule-based policy modeling for supply-side advertising platforms, covering inventory modeling, rule inheritance and overrides, conflict resolution, real-time evaluation, and operational controls like validation, versioning, rollout, and auditing.

    System DesignOnsite
  • NetflixMediumSoftware Engineer
    Design Rolling-Window Ad Frequency Capping

    This question evaluates system-design skills for building scalable, low-latency services that enforce time-based rolling-window state, including data modeling for impression history, read/write paths, concurrency control, and fault tolerance; category: System Design.

    System DesignOnsite
  • NetflixMediumSoftware Engineer
    Design a Distributed Frequency-Capping Service

    Tests the ability to design an ultra-low latency, highly available counting and rate-limiting system for ad frequency capping across distributed environments, balancing consistency with latency trade-offs.

    System DesignOnsiteDistributed SystemsCachingAdTech
  • NetflixHardSoftware Engineer
    Design a File Backup System

    This question evaluates understanding of scalable system design, file synchronization and metadata handling, data consistency, fault tolerance, and performance trade-offs involved in designing a file backup system.

    System DesignTechnical Screen
  • NetflixMediumSoftware Engineer
    Design a Job Scheduler for ML Training and Batch Inference on a Shared Cluster

    Design a job scheduler for machine learning workloads such as training runs and batch inference on a shared compute cluster with GPUs. It tests requirements gathering, queueing and fairness between teams, gang placement for distributed jobs, preemption and checkpointing, and recovery from node and scheduler failures.

    System DesignTechnical Screen
  • NetflixMediumSoftware Engineer
    Design a Scheduler for ML Training and Batch Inference Jobs

    This question tests the ability to design a distributed job scheduler capable of handling heterogeneous ML workloads with varying priority, resource requirements, and fault-tolerance constraints.

    System DesignOnsiteDistributed SystemsSchedulingResource Management
  • NetflixMediumSoftware Engineer
    Design a Streaming Subscription System: Billing, Plan Changes and Payment Retries

    Design the subscription backend of a video streaming service such as Netflix, covering the subscription lifecycle, recurring billing through an external payment provider, mid-cycle upgrades and downgrades, retries of failed charges, and scaling. It tests data modeling, safe payment handling, concurrency between member actions and billing jobs, and keeping entitlement checks fast.

    System DesignOther
  • NetflixEasySoftware Engineer
    Design a crash-resilient file system

    This question evaluates understanding of durable storage and crash recovery mechanisms in file system design, including metadata consistency, durability guarantees, and operational concerns like performance and space overhead.

    System DesignTechnical Screen
  • NetflixMediumSoftware Engineer
    Design ad frequency capping

    This question evaluates a candidate's competence in large-scale system design, including distributed systems, real-time analytics, data modeling, and consistency and scalability trade-offs for ad frequency capping.

    System DesignOnsite
  • NetflixHardSoftware Engineer
    Design ads frequency capping service

    This question evaluates a candidate's ability to design a low-latency, high-QPS, multi-tenant frequency capping service, testing competencies in identity resolution, hierarchical cap modeling, window semantics, counter and storage architecture, consistency versus latency trade-offs, real-time decisioning APIs, configuration/versioning, backfill, reporting, privacy/compliance, and failure handling. It is commonly asked to assess systems-design proficiency in distributed systems, databases, caching, API design, and operational reliability; it belongs to the System Design domain and emphasizes practical application with system-level conceptual reasoning rather than purely algorithmic detail.

    System DesignOnsite
  • NetflixHardSoftware Engineer
    Design an Ad Pacing System

    This question evaluates a candidate's skill in designing large-scale, low-latency distributed advertising systems, including pacing algorithms, budgeting and spend tracking, concurrency control, event processing, and observability.

    System DesignOnsite
  • NetflixHardSoftware Engineer
    Design an ad frequency capping system

    This question evaluates competency in distributed systems architecture, real-time stateful services, high-cardinality time-series data modeling, API design for low-latency decision paths, and operational monitoring including consistency and latency trade-offs.

    System DesignOnsite
  • NetflixHardSoftware Engineer
    Design an ads audience targeting system

    This problem evaluates your ability to design a high-scale, low-latency system for filtering user profiles against complex, dynamic advertising audience segments.

    System DesignTechnical ScreenScalabilityDistributed SystemsCaching
  • NetflixMediumSoftware Engineer
    Design an ads data model

    This problem tests your ability to design a scalable, reliable data schema for an advertising platform that must support high-throughput event ingestion and real-time analytical queries.

    System DesignOnsiteData ModelingScalabilityOLTP vs OLAP
  • NetflixHardData Engineer
    Design config rollout and click aggregation

    This problem tests your ability to design a global configuration distribution system combined with a high-throughput event processing pipeline to monitor rollout health.

    System DesignOnsiteDistributed SystemsReal-time AnalyticsEvent Streaming
  • NetflixMediumSoftware Engineer
    Design homepage viewport rendering with deduplication

    This problem tests the ability to design a content-delivery service that optimizes viewport rendering through client-side requests, server-side deduplication, and efficient data retrieval patterns.

    System DesignTechnical ScreenAPI DesignCachingHigh Availability
  • NetflixHardSoftware Engineer
    Design viewport dedup for Netflix home page

    Design viewport dedup for Netflix home page 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 DesignTechnical Screen
  • NetflixMediumSoftware Engineer
    Model ads demand data for reporting

    This question tests the ability to design a robust data pipeline and schema for tracking ad performance metrics, focusing on handling event-level data, aggregations, and dimension consistency.

    System DesignOnsiteData EngineeringData ModelingETL
  • NetflixMediumSoftware Engineer
    Model data for an ads platform

    This question evaluates proficiency in data modeling and database schema design for advertising systems, including entity-relationship modeling, privacy-aware user identifier handling, and delivery/tracking log representation.

    System DesignOnsite
  • New RelicMediumBackend Engineer
    Design a Kafka Consumer Service That Groups Trace Events by Trace ID

    Design a distributed service that consumes trace events from Kafka, groups every event sharing a trace ID, and hands each complete trace to an existing processing function. Covers partitioning, in-memory versus external state, deciding when a trace is complete, and traces that stay open for hours.

    System DesignOnsite
  • NextdoorHardSoftware Engineer
    Describe CAP, distributed systems, multithreading experience

    This question evaluates practical and theoretical competence in the CAP theorem, distributed system architecture, and multithreaded concurrency, covering consistency models, partition tolerance, fault tolerance, scaling strategies, synchronization primitives, and debugging/performance techniques.

    System DesignHR Screen
  • NextdoorHardData Engineer
    Design KPI dashboard tables: retention, weekly rollups, timezone

    This Nextdoor data engineer system design screen asks you to design the analytical data model and incremental ETL behind a fast, large-scale KPI dashboard for a photo-sharing app. It covers derived aggregate table design (grain, keys, partitioning), DAU/new-user/new-photo and follower-distribution metrics, 7-day deltas, then extends to week-1 cohort retention, weekly rollups, and switching the reporting timezone. The focus is correctness, performance at scale, and maintainability with timezone handled as a reporting parameter.

    System DesignTechnical Screen
  • NextdoorMediumSoftware Engineer
    Design a Job Scheduler That Can Scale by 100 Times

    Design a distributed, asynchronous job scheduler that starts at modest traffic but can seamlessly scale up 100x. Evaluates API design, data storage trade-offs, worker coordination, task deduplication, and failure handling across scale boundaries.

    System DesignTechnical ScreenDistributed SystemsJob SchedulerScalability
  • NextdoorMediumSoftware Engineer
    Design a Neighborhood Newsfeed System

    Design a privacy-aware, hyperlocal social feed that serves real-time updates and emergency alerts based on strict neighborhood boundaries.

    System DesignTechnical ScreenFeed ArchitectureGeospatialDistributed Systems
  • NextdoorMediumSoftware Engineer
    Design a Scalable Job Scheduler

    This question evaluates system design skills focused on job scheduling, distributed systems concerns (state modeling, retries, idempotency), API and data-model design, fault tolerance, observability, and scalability within the System Design domain.

    System DesignTechnical Screen
  • NielsenMediumSoftware Engineer
    Design a URL Shortening Service: Code Generation, Storage and Fast Redirects

    A system design question on building a URL shortening service that turns long links into short codes and redirects visitors quickly at large scale. It tests requirement scoping, capacity estimates, collision-free code generation across servers, storage and caching choices, and how the redirect path behaves under failure.

    System DesignOther
  • NooksMediumSoftware Engineer
    How would you throttle a crawler?

    This question evaluates competency in scalable distributed system design, including rate limiting, request scheduling, concurrency control, fault tolerance, backoff/retry strategies, deduplication, and observability for networked crawlers.

    System DesignOnsite
  • NotionMediumSoftware Engineer
    Design a Shared Calendar Service

    This problem tests the ability to design a scalable shared calendar system with support for recurring events, granular permission models, and notification scheduling.

    System DesignOnsiteDatabase SchemaScalabilityAsynchronous Processing