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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.
- 9403
- Questions
- 546
- Companies
- 11
- Topics
- 8
- Languages
Showing 541–570 of 4616 results
- AppleMediumSoftware EngineerDecode a Run-Length Encoded String Where a Missing Count Means One
Implement a decoder for run-length encoded strings in which each lowercase letter is followed by an optional repeat count, so that a5b3c becomes aaaaabbbc. It tests careful string parsing, multi-digit counts, letters written without a count, and writing your own test cases.
Coding & AlgorithmsTechnical Screen - AppleMediumData ScientistDescribe Your Role in a Recent Successful Project
This interview question evaluates behavioral evidence, ownership, communication, trade-offs, and measurable outcomes in a realistic interview setting. A strong answer for Describe Your Role in a Recent Successful Project states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Behavioral & LeadershipTechnical Screen - AppleMediumSoftware EngineerDescribe common RTL lint warnings and errors
This question evaluates understanding of RTL static analysis and common lint warnings/errors in Verilog/SystemVerilog, testing competence in diagnosing issues such as modules treated as black boxes, combinational loops, and width mismatches.
Software Engineering FundamentalsTechnical Screen - AppleMediumMachine Learning EngineerDescribe recent project experiences
Describe recent project experiences evaluates behavioral evidence, ownership, communication, trade-offs, and measurable outcomes in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Behavioral & LeadershipTechnical Screen - AppleMediumSoftware EngineerDescribe your most memorable bug and fix
Evaluates debugging, root-cause analysis, incident response, communication, and ownership skills for a Software Engineer within the Behavioral & Leadership domain.
Behavioral & LeadershipTechnical Screen - AppleMediumSoftware EngineerDescribe your recent project and scope
Describe your recent project and scope evaluates behavioral evidence, ownership, communication, trade-offs, and measurable outcomes in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Behavioral & LeadershipTechnical Screen - 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 - 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 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 - 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 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 - 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 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 - 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.
Coding & AlgorithmsTechnical Screengraphbfsdfs - AppleMediumFrontend EngineerDiagnose Cold-Load and Massive-Table Performance in a Web App
This problem tests your understanding of critical path rendering optimization for cold loads and memory management strategies for handling massive datasets in a browser environment.
Software Engineering FundamentalsTechnical ScreenPerformanceDOMReact - AppleMediumData ScientistDiagnose post-release conversion regression rigorously
This question tests the ability to diagnose a post-release metric regression in the absence of a control group by utilizing quasi-experimental design and causal inference methods.
Analytics & ExperimentationTechnical ScreenCausal InferenceRoot Cause AnalysisExperimentation - AppleHardData EngineerDiscuss Challenges and Career Goals
This question evaluates problem-solving, technical depth, communication, leadership, and career-motivation competencies relevant to a Data Engineer role within the Behavioral & Leadership category.
Behavioral & LeadershipTechnical Screen - AppleHardData EngineerEncode and Rebuild a Binary Tree
This question evaluates skills in data structure serialization and deserialization, binary tree representation, and algorithmic design for deterministic data formats.
Coding & AlgorithmsTechnical Screen - AppleMediumData ScientistExamine Data to Boost Instagram Purchases Effectively
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 Examine Data to Boost Instagram Purchases Effectively states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Analytics & ExperimentationTechnical Screen - AppleMediumSoftware EngineerExplain HashMap Resizing Without Long Pauses
This question evaluates understanding of hash map internals—how keys are mapped to buckets, collision resolution strategies, and when and why resizing occurs—testing competence in data structures and performance engineering within the Software Engineering Fundamentals domain.
Software Engineering FundamentalsTechnical Screen - AppleMediumFrontend EngineerExplain JavaScript Scope, Closures, Timers, and the Event Loop
Tests deep understanding of the JavaScript runtime, specifically lexical scope, closures, the distinction between task and microtask queues in the event loop, and browser script loading mechanics.
Software Engineering FundamentalsTechnical ScreenJavaScriptEvent LoopClosures - AppleMediumSoftware EngineerExplain Python lists, dicts, and concurrency
Explain Python lists, dicts, and concurrency evaluates SQL or pandas logic, joins, grouping, window functions, null handling, edge cases, and validation in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Data Manipulation (SQL/Python)Technical Screen - AppleMediumSoftware EngineerExplain Runnable vs Callable and thread-safe Singleton
This question tests the conceptual differences between Java concurrency interfaces and the practical implementation of thread-safe creational design patterns.
Software Engineering FundamentalsTechnical ScreenJavaConcurrencyDesign Patterns
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