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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.
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Showing 1231–1260 of 9403 results
- AppleMediumData ScientistDesign A/B Test for Search Feature Effectiveness
This interview question evaluates metric design, causal reasoning, experiment setup, diagnostics, SQL/statistical checks, and recommendations in a realistic interview setting. A strong answer for Design A/B Test for Search Feature Effectiveness states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Analytics & ExperimentationTechnical Screen - AppleEasySoftware EngineerDesign APIs for a Voting System
Define APIs and a core model for an authenticated election with one final ballot per voter and results hidden until close. The design discussion covers eligibility, deterministic timing, idempotent voting, concurrent submissions, recountable records, audit trails, and privacy boundaries.
System DesignTechnical Screen - AppleMediumMachine Learning EngineerDesign App Store search
This question evaluates a candidate's ability to design scalable, low-latency app marketplace search systems, covering competencies in query understanding, metadata ingestion and indexing, candidate retrieval and ranking, personalization, multilingual and typo-tolerant handling, cold-start and spam prevention, as well as online experimentation and monitoring. Commonly asked in the ML system design/search engineering domain to probe architectural trade-offs, measurement of product requirements and success metrics, and operationalization, it spans both high-level conceptual reasoning and practical application details.
ML System DesignOnsite - AppleMediumMachine Learning EngineerDesign CI/CD for AI Services
This question evaluates the ability to design a scalable CI/CD and MLOps platform that integrates backend services, model-serving APIs, data and feature pipelines, Kubernetes-based deployments, artifact and model versioning, security, and observability.
System DesignOnsite - AppleMediumSoftware EngineerDesign Cloud Photo Storage and Multi-Device Sync
Design a scalable cloud photo storage and multi-device synchronization system supporting resilient media uploads, conflict-free sync, and bandwidth-efficient thumbnail and preview generation.
System DesignOnsitesystem-designcloud-storagedata-synchronization - AppleMediumSoftware EngineerDesign Cross-Device Wallpaper Synchronization
This question tests the ability to design a distributed synchronization system that balances low-latency local updates with eventually consistent cross-device state, focusing on conflict resolution, bandwidth optimization, and offline-first availability.
System DesignOnsiteDistributed SystemsSynchronizationOffline-first - AppleMediumSoftware EngineerDesign Disk-Based Inventory Serving
This question evaluates a candidate's ability to design disk-based inventory services under tight RAM constraints, focusing on data layout, indexing strategies, caching, write/read paths, conditional updates, concurrency control, and I/O-latency trade-offs.
System DesignTechnical Screen - AppleMediumData ScientistDesign Siri-vs-GPT query routing
This question evaluates a data scientist's competency in designing an end-to-end query-routing system between an on-device personal assistant and a large language model assistant, encompassing objectives, success metrics, ground-truth labeling, feature and model choices, ambiguity and multi-turn handling, and evaluation strategies.
Machine LearningTechnical Screen - AppleMediumData EngineerDesign TikTok Data Engineering Systems
This problem tests the ability to design an end-to-end data pipeline for high-throughput mobile app event logging, focusing on ingestion, transformation, and storage optimization.
System DesignTechnical ScreenData PipelinesDistributed SystemsOLAP - AppleHardSoftware EngineerDesign a 200-Terabyte Media Migration and Training Input Pipeline
This problem tests your ability to design a high-throughput data ingestion pipeline, focusing on network bottlenecks, storage strategies, and synchronization between on-premises assets and cloud-based training clusters.
ML System DesignTechnical ScreenSystem DesignData EngineeringMLOps - AppleMediumMachine Learning EngineerDesign a CPA system for ad bidding
This question tests the ability to design an end-to-end Cost-Per-Acquisition (CPA) bidding system, specifically focusing on how to model conversion probabilities and handle the complexities of delayed feedback and bid pacing.
ML System DesignTechnical ScreenSystem DesignML OpsAdTech - AppleMediumSoftware EngineerDesign a Centralized Logging System
Tests the candidate's ability to design a high-throughput, distributed log collection and search platform, balancing ingestion backpressure, index cost, query latency, and tiered storage.
System DesignOnsiteDistributed SystemsLoggingStreaming - AppleMediumSoftware EngineerDesign a Distributed Token-Bucket Rate Limiter
This problem tests the ability to design a scalable, low-latency distributed rate-limiting service using the token bucket algorithm while balancing consistency and performance.
System DesignOnsiteDistributed SystemsRate LimitingCaching - AppleMediumSoftware EngineerDesign a Population-Weighted Random Country Picker
This problem tests your ability to implement a weighted sampling algorithm efficiently and write testable code by decoupling randomness.
Software Engineering FundamentalsTechnical ScreenAlgorithmsBinary SearchProbability - AppleMediumAccessories Software QA EngineerDesign a Score for Imperfect Palindromes
Design an interpretable palindrome-resemblance score with explicit character handling, similarity features, weights, edge cases, and computational trade-offs.
System DesignOnsite - AppleMediumSoftware EngineerDesign a Service for the Top K Most-Visited URLs over a Sliding Time Window
A system design question on reporting the top K most-visited URLs over a sliding time window. It tests requirement clarification, stream ingestion and windowed counting, merging per-partition top-K results correctly, serving precomputed rankings, and handling hot keys, late events and exact versus approximate counts.
System DesignOnsite - AppleMediumSoftware EngineerDesign a deck of cards with shuffle/draw
This question evaluates object-oriented design skills, understanding of randomness and probability in algorithms, and analysis of time/space complexity for data structures and operations.
Software Engineering FundamentalsTechnical Screen - AppleMediumMachine Learning EngineerDesign a grounded voice assistant
This problem evaluates your ability to design a retrieval-augmented generation (RAG) system for a voice assistant, focusing on grounding model outputs in trusted sources to prevent hallucinations.
ML System DesignOnsiteRAGLLMSystem Design - AppleMediumMachine Learning EngineerDesign a multimodal RAG assistant
This question evaluates system design and machine learning engineering skills for building a multimodal Retrieval-Augmented Generation (RAG) assistant, covering competencies in data ingestion and preprocessing across modalities, indexing and retrieval strategies, embeddings and re-ranking, grounding/prompting with citations, and evaluation and failure-mode mitigation. It is commonly asked to gauge an engineer's ability to architect scalable, grounded QA pipelines that balance retrieval quality, latency, and cost; it sits in the System Design domain and tests both high-level architectural reasoning and practical implementation considerations.
System DesignTechnical Screen - AppleMediumSoftware EngineerDesign a rolling five-minute hit counter
This question evaluates understanding of data-structure selection, amortized time complexity, space-time trade-offs, sliding-window state management for expiring events, and the ability to design a concise API with unit tests.
Coding & AlgorithmsTechnical Screen - AppleHardSoftware EngineerDesign a smartwatch sensor subsystem
This question tests your ability to design a resource-constrained embedded sensing subsystem, focusing on the trade-offs between energy efficiency, data latency, and algorithmic reliability in a wearable device.
System DesignOnsiteEmbedded SystemsPower OptimizationSensor Fusion - AppleMediumSoftware EngineerDesign a snapshotable key-value store
This interview question evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer for Design a snapshotable key-value store states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsTechnical Screen - AppleHardMachine Learning EngineerDesign a streaming embedding-based classifier
This question evaluates a candidate's ability to design end-to-end streaming machine learning systems, including online text preprocessing, tokenization, embedding generation, continuous model training, and low-latency classification serving.
ML System DesignTechnical Screen - AppleMediumSoftware EngineerDesign ad click aggregator and file sync service
This question tests the ability to design a high-throughput event processing system for ad clicks and a scalable file synchronization service, focusing on data consistency, idempotency, and distributed storage patterns.
System DesignOnsiteDistributed SystemsData IngestionConsistency - AppleMediumData ScientistDesign an A/B Test for Homepage Layout Impact
This interview question evaluates metric design, causal reasoning, experiment setup, diagnostics, SQL/statistical checks, and recommendations in a realistic interview setting. A strong answer for Design an A/B Test for Homepage Layout Impact states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Analytics & ExperimentationOnsite - AppleMediumSoftware EngineerDesign an Accurate Click Aggregator
This question tests the ability to design a high-throughput, fault-tolerant system for tracking ad clicks while ensuring exactly-once processing or deduplication at scale.
System DesignTechnical ScreenScalabilityData PipelineDeduplication - AppleHardSoftware EngineerDesign and scale a Yelp-like platform
This question evaluates system design and engineering skills including data modeling, indexing, geospatial and full-text search, caching, replication and sharding for a high-scale reviews platform, together with key generation, storage layout, redirects, rate limiting and analytics for a URL-shortening service, probing the ability to balance scalability, consistency, availability, and operational complexity. It falls under the System Design / Distributed Systems / Databases domain and is commonly asked to assess architectural reasoning and trade-off analysis, testing both conceptual high-level design and practical implementation considerations such as performance, fault tolerance, and operational constraints.
System DesignOnsite - AppleMediumSoftware EngineerDesign card deck with shuffle and order
This question evaluates understanding of data modeling and API design for a deck abstraction, algorithmic handling of randomization and sorting, and the ability to analyze time and space complexity.
Coding & AlgorithmsOnsite - AppleHardSoftware EngineerDesign video platform and catalog system
This System Design question evaluates proficiency in large-scale architecture, API and storage design, data modeling, scalability and consistency trade-offs, ingestion and indexing pipelines, CDN and caching strategies, and operational concerns such as reliability, observability, security, and multi-region deployments across video-sharing and marketplace catalog domains. It is commonly asked in technical interviews to test architectural judgment and trade-off reasoning, emphasizing high-level practical application and operational planning rather than low-level implementation details.
System DesignOnsite - AppleMediumSoftware EngineerDetermine Whether an Undirected Graph Is Two-Colorable
Determine whether an undirected graph with disconnected components, potential self-loops, and parallel edges can be colored using two colors such that no two adjacent vertices share the same color.
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