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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 241–270 of 4616 results
- AmazonHardSoftware EngineerDesign a keyboard and mouse input system
An Amazon software-engineer system-design screen: design a system that captures keyboard and mouse events and reconstructs exactly what the user typed. It tests low-latency event capture, total ordering across multiple devices, IME/composition and grapheme-safe text reconstruction, mouse selection and clipboard/undo-redo, plus durable persistence with deterministic crash-safe replay.
System DesignTechnical Screen - AmazonMediumSoftware EngineerDesign a large-scale temperature sensor system
This question tests your ability to design a high-throughput data ingestion pipeline and storage architecture for a fleet of IoT sensors, focusing on write-heavy scalability and time-series query performance.
System DesignTechnical ScreenTime-SeriesScalabilityDistributed Systems - AmazonHardSoftware EngineerDesign a log filtering and analytics service
An Amazon software engineer system design question: design a log filtering and analytics service that ingests high-volume application logs and supports attribute/substring filtering, error counts over a time window, and hourly histograms by pattern or ID. It tests ingestion API design, dual search + OLAP storage with hourly rollups, schema and indexing, late/duplicate-event handling, partitioning and retention, and correctness-vs-latency trade-offs with complexity analysis.
System DesignTechnical Screen - AmazonHardSoftware EngineerDesign a memory usage switcher with thresholds
This question evaluates system design and operational engineering skills in process memory management, runtime configurability, observability, and reliability, and belongs to the System Design domain; it primarily tests practical application with system-level conceptual reasoning.
System DesignTechnical Screen - AmazonMediumSoftware EngineerDesign a package installer with dependencies
This question tests your ability to design a system that manages complex dependency graphs, ensuring package integrity, version compatibility, and atomic installation operations.
System DesignTechnical ScreenGraphsDependency ResolutionTransactions - AmazonMediumSoftware EngineerDesign a pizza ordering system
This question evaluates object-oriented design and software architecture skills, focusing on class modeling, responsibilities, relationships, state management, pricing, payment flows, and extensibility.
Software Engineering FundamentalsTechnical Screen - AmazonHardData ScientistDesign a robust traffic forecasting pipeline
This question tests the ability to design an end-to-end, scalable time-series forecasting pipeline, focusing on anomaly handling, structural decomposition, uncertainty quantification, and model validation strategies.
Machine LearningTechnical ScreenTime-SeriesForecastingState-Space Models - AmazonHardSoftware EngineerDesign a scalable parking lot system
Design a scalable parking lot system 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 - AmazonMediumSoftware EngineerDesign a weighted random value generator
This problem tests your ability to implement efficient weighted random selection using prefix sums and binary search, and handling state updates.
Coding & AlgorithmsTechnical ScreenBinary SearchHash MapProbability - AmazonMediumSoftware EngineerDesign an AI Fraud-Triage Agent Over a 1 TB/Day Payments Event Stream
Design a service where an AI agent investigates flagged payment events inside a stream running at roughly 1 TB of events per day, covering capacity math, where the agent sits relative to deterministic detection, and the cost and adversarial-input guardrails that keep it from becoming a liability.
System DesignTechnical Screensystem-designstreamingfraud - AmazonEasySoftware EngineerDesign an Amazon Locker Service
Tests object-oriented design and state-machine modeling for a self-service package locker station, focusing on parcel allocation, code expiration, and physical-vs-logical state consistency.
System DesignTechnical ScreenObject-Oriented DesignState MachineIoT - AmazonMediumData ScientistDesign an Automated Home-Price Valuation Model
Design an Automated Home-Price Valuation Model evaluates core ML concepts, assumptions, math intuition, training/evaluation trade-offs, and practical failure modes in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Machine LearningTechnical Screen - AmazonMediumSoftware EngineerDesign an Extensible Cinema Ticket Pricing Engine
Design an extensible cinema pricing engine with validated money and multiplier types, composable policies, explicit calculation and rounding, compatibility checks, versioned configuration, itemized quotes, and boundary tests.
Software Engineering FundamentalsTechnical Screen - AmazonMediumSoftware EngineerDesign an In-Memory Pub-Sub Model
This question evaluates object-oriented design and API modeling skills, knowledge of messaging/pub-sub semantics, concurrency and thread-safety, and the ability to reason about extensibility for retries, persistence, and asynchronous delivery.
Software Engineering FundamentalsTechnical Screen - AmazonMediumSoftware EngineerDesign an Object-Oriented Shopping Cart
Tests object-oriented design principles, domain modeling for monetary precision, extensible discount strategies, and thread-safe state mutations.
Software Engineering FundamentalsTechnical ScreenObject-Oriented DesignDesign PatternsConcurrency - AmazonMediumApplied ScientistDesign an advertiser metrics tracking platform
This question tests your ability to design a flexible, object-oriented system for ingesting, processing, and querying real-time advertising performance metrics.
Software Engineering FundamentalsTechnical ScreenSystem DesignOOPDesign Patterns - AmazonHardSoftware EngineerDesign an e-commerce recommendation system
This question evaluates expertise in large-scale machine learning system design, covering competencies in recommendation algorithms, candidate generation and ranking, feature engineering and stores, low-latency serving, and operational reliability; it is categorized in the ML system design domain and requires both conceptual understanding and practical application. It is commonly asked to assess the ability to balance personalization and business metrics (CTR, CVR, revenue), address scalability and latency targets, and manage data quality, cold-start, exploration–exploitation, A/B testing, bias/fairness, and monitoring trade-offs in production.
ML System DesignTechnical Screen - AmazonHardSoftware EngineerDesign an email spam detection system
This interview question evaluates ML product requirements, data/labeling, modeling, serving architecture, evaluation, monitoring, and trade-offs in a realistic interview setting. A strong answer for Design an email spam detection system states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
ML System DesignTechnical Screen - AmazonHardData ScientistDesign an end-to-end spam detection system
This question evaluates a data scientist's system-design and applied machine learning engineering skills—covering problem framing and labeling, feature representation, model selection and calibration, real-time serving constraints, drift detection, and feedback/safety mechanisms—and is commonly asked to probe trade-offs between latency, precision/recall, and robustness against adversarial evolution in production spam detection. Category: Machine Learning; it tests machine learning systems and production-ML competencies at both conceptual-design and practical-application levels, emphasizing calibration, evaluation (offline and online), operational reliability, and rollback/mitigation planning.
Machine LearningTechnical Screen - AmazonHardSoftware EngineerDesign an extensible ticketing system
This question evaluates software architecture and system-design competencies, covering extensibility patterns, concurrency control for high-throughput ticketing, transactional and idempotency guarantees, persistence/schema modeling, API design, and pluggable pricing strategies.
System DesignTechnical Screen - AmazonHardSoftware EngineerDesign an intersection traffic-light system
This question evaluates system design competency across real-time control and safety-critical logic, API and data modeling, sensor/actuator integration, and operational scalability for traffic-signal controllers.
System DesignTechnical Screen - AmazonEasyData ScientistDesign and evaluate a RAG system
This question evaluates a candidate's competency in designing and evaluating retrieval-augmented generation (RAG) systems, including document ingestion, chunking, embedding and retrieval strategies, reranking, prompt construction, grounding/citation, operational constraints like latency and freshness, permission handling, and evaluation metrics and failure modes. It is commonly asked to assess practical system-design and applied machine learning skills for LLM applications, testing knowledge in the Machine Learning/Information Retrieval domain and requiring both practical application-level reasoning about trade-offs (latency, cost, precision vs. recall) and conceptual understanding of evaluation and guardrails.
Machine LearningTechnical Screen - AmazonHardSoftware EngineerDesign in-memory threshold switcher
This question evaluates a candidate's ability to design memory-aware control systems, covering skills such as hysteresis-based thresholding, dynamic runtime reconfiguration, thread-safe concurrency, low-overhead metric sampling, event-driven state notifications, and handling multi-process and failure edge cases.
System DesignTechnical Screen - AmazonHardSoftware EngineerDesign locker allocation service
This question evaluates a candidate's understanding of stateful system design, resource allocation strategies, concurrency control, API and data modeling, and fault tolerance in the context of real-time locker assignment.
System DesignTechnical Screen - AmazonMediumSoftware EngineerDesign pickup point planning for ride-hailing
Design a ride-hailing pickup-point planning system. Covers map snapping, candidate generation, driver and passenger routing, safety filtering, scoring objectives, app presentation, architecture, historical learning, and A/B metrics.
System DesignTechnical Screen - AmazonHardSoftware EngineerDesign real-time top-K products service
An Amazon software-engineer system-design screen: design a real-time service that ingests a stream of purchase events (customer_id, item_id, timestamp) and continuously serves the top-K most purchased items over multiple rolling windows (e.g. last 5 minutes, last 1 hour, 24 hours, and daily totals). The answer covers ingestion and partitioning, event-time windowing with watermarks, exact min-heap vs. approximate Count-Min-Sketch / Space-Saving top-K, late/duplicate/out-of-order handling, state and TTL, exactly-once fault tolerance, horizontal scaling, serving APIs, and latency-vs-accuracy trade-offs.
System DesignTechnical Screen - AmazonHardSoftware EngineerDesign secure multi-tier cloud infrastructure
This question evaluates cloud systems design competencies including multi-tier network architecture, IP addressing and capacity planning, security controls, centralized server management, shared storage trade-offs, and identity and access integration within a production-scale virtual private cloud.
System DesignTechnical Screen - AmazonMediumSoftware EngineerDetect and Break a Cycle in a Singly Linked List
Tests detection and resolution of cycles in singly linked lists using two-pointer techniques with constant auxiliary space.
Coding & AlgorithmsTechnical Screenlinked-listtwo-pointersfloyds-algorithm - AmazonMediumSoftware EngineerDetect cycles in lists and graphs
This question evaluates understanding of cycle detection in linked lists and directed graphs, assessing competencies in pointer manipulation, graph traversal strategies, and reasoning about algorithmic time and space complexity within the Coding & Algorithms domain.
Coding & AlgorithmsTechnical Screen - AmazonMediumSoftware EngineerDetect words formed by multiple dictionary parts
This question evaluates proficiency in string processing, selection and use of appropriate data structures and algorithms (hashing, tries), dynamic programming and memoization, and complexity analysis for large inputs and edge-case handling within the Coding & Algorithms domain.
Coding & AlgorithmsTechnical Screen
Amazon