Katkat

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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 3181–3210 of 9403 results

  • EngelhartMediumSoftware Engineer
    Exposing a Python Function as a REST Endpoint with FastAPI and Unit Testing It

    An interview question on exposing a Python function as a REST API endpoint and testing it. It asks whether FastAPI counts as an endpoint, how an endpoint maps an HTTP request onto a function, and how you unit test such code, with a concrete example that covers edge cases and replaced dependencies.

    Software Engineering FundamentalsTechnical Screen
  • EngelhartMediumSoftware Engineer
    Python Abstract Classes and Instance, Class and Static Methods

    A Python object-oriented programming interview question on abstract classes and method kinds. It asks what an abstract class is and whether it can be instantiated, how instance, class and static methods differ, what self and cls refer to, and why a static method would live inside a class at all.

    Software Engineering FundamentalsTechnical Screen
  • EngelhartMediumSoftware Engineer
    Python Dictionary Internals: Hashing, Collisions, O(1) Lookup and Hashable Keys

    A Python fundamentals interview question on how dictionaries store and look up values: what gets hashed, whether different keys can share a hash, how collisions are resolved and why average lookup is constant time. It also tests whether a list can serve as a key and which objects are allowed as keys.

    Software Engineering FundamentalsTechnical Screen
  • EngelhartMediumSoftware Engineer
    Python Generators, yield, Lazy Evaluation and How Decorators Work

    A Python interview question on generators and decorators. It asks what a generator is, what yield does, why generators use less memory and what lazy evaluation means, then what a decorator actually does under the hood, testing precise language mechanics rather than memorized definitions.

    Software Engineering FundamentalsTechnical Screen
  • EngelhartMediumSoftware Engineer
    Python Virtual Environments, Conda and Poetry, and Everyday Linux Commands

    A developer tooling interview question on Python virtual environments, why projects need them and how Conda and Poetry fit in, followed by practical Linux experience: which system you work on and which Unix commands you rely on to run and debug jobs on a server.

    Software Engineering FundamentalsTechnical Screen
  • EngelhartMediumSoftware Engineer
    Relational Database Indexes: Read/Write Trade-offs and Tuning a Slow SQL Query

    A database fundamentals interview question on relational indexes: what an index is, why it speeds up queries, why not every column should be indexed and how indexes affect write performance. It then asks how you would troubleshoot and tune a complex SQL query that runs extremely slowly.

    Software Engineering FundamentalsTechnical Screen
  • EngelhartMediumSoftware Engineer
    Threads vs Processes, the Python GIL, Multiprocessing and Async I/O

    A Python concurrency interview question covering how threads and processes differ, including their memory spaces, when to reach for multiprocessing, what the Global Interpreter Lock is and how it limits CPU-bound threads, and why async I/O is a good fit for network and other I/O-bound workloads.

    Software Engineering FundamentalsTechnical Screen
  • EnigmaMediumSoftware Engineer
    Search Book Titles

    This question evaluates proficiency in string processing, tokenization, case-insensitive matching, anagram detection, and algorithmic design for efficient search and deduplication.

    Coding & AlgorithmsTechnical Screen
  • Epic SystemsMediumSoftware Engineer
    Encode Letters with a Telephone Keypad

    Tests string manipulation, hash-table lookup, and state tracking by converting an alphanumeric string into multi-tap keypad strokes with pause delimiters.

    Coding & AlgorithmsOnline AssessmentStringHash TableImplementation
  • Epic SystemsMediumSoftware Engineer
    Solve Coin, Growth, Time, and Rate Problems

    This problem tests analytical thinking and basic arithmetic under time pressure, focusing on rate of change and compound logic.

    Statistics & MathOnline AssessmentMathLogicExponential Growth
  • Epic SystemsHardSoftware Engineer
    Solve Timed Logical and Quantitative Reasoning Cases

    Implement a deduction engine that evaluates whether target query statements are definitely true, definitely false, or cannot be determined, given a set of observed facts and unidirectional logical implications.

    Software Engineering FundamentalsOnline AssessmentGraph AlgorithmsLogic DeductionBFS/DFS
  • EquinixMediumFrontend Engineer
    Plan Testing and Deployment for a React Feature

    This question assesses a candidate's ability to architect a robust, production-ready React feature by integrating state persistence, error handling, testing strategies, and safe deployment practices.

    Software Engineering FundamentalsHR ScreenReactFrontend ArchitectureTesting Strategy
  • EquinixMediumSoftware Engineer
    Review AI Platform And Software Fundamentals

    This problem tests foundational knowledge in software architecture, AI system design, and data structures by requiring the candidate to explain the trade-offs in building a RAG-based document retrieval system.

    Software Engineering FundamentalsTechnical ScreenRAGSystem DesignSOLID
  • EricssonMediumSoftware Engineer
    Solve Triangle Rows and Top Frequencies

    This question set evaluates understanding of combinatorial number patterns and frequency-based selection, specifically the ability to generate an additive number triangle and to identify the k most frequent elements, assessing skills in array/list manipulation, counting, and selection algorithms.

    Coding & AlgorithmsTechnical Screen
  • EthosMediumSoftware Engineer
    Find Array Elements Uniquely Determined by Known Range Sums

    Given only the index ranges whose sums are known for a hidden integer array, list every position whose value is uniquely determined by those sums, or report -1 if none is. Tests reasoning about how overlapping and nested range sums combine, plus an efficient solution for 100,000 ranges.

    Coding & AlgorithmsOnline Assessment
  • EtsyMediumData Scientist
    Implement streaming autocomplete under tight memory

    This question evaluates a candidate's ability to design a memory- and latency-constrained autocomplete service, testing skills in data structure selection, string/Unicode normalization, approximate string matching, concurrency, dynamic updates, and algorithmic time/space analysis.

    Coding & AlgorithmsTechnical Screen
  • EvenUpMediumSoftware Engineer
    Answer common recruiter behavioral questions

    This set evaluates interpersonal and behavioral competencies—communication, self-reflection, stress management, and the ability to translate technical ideas—within the Behavioral & Leadership domain for a Software Engineer role.

    Behavioral & LeadershipOnline Assessment
  • EvenUpMediumData Scientist
    Build a model to predict wine quality

    This question evaluates predictive modeling and data-science competencies—exploratory data analysis, feature assessment, problem framing (regression vs classification vs ordinal), model selection and validation, evaluation metric choice, and post-model feature-importance interpretation—in the Machine Learning domain, combining conceptual understanding with practical application. It is commonly asked in technical interviews for Data Scientist roles because it tests end-to-end modeling judgment, reasoning about data distributions and variable usefulness, selection of validation and evaluation strategies, and awareness of pitfalls such as collinearity and data leakage.

    Machine LearningTechnical Screen
  • EvenUpMediumSoftware Engineer
    Walk through your resume and impacts

    This interview question evaluates behavioral evidence, ownership, communication, trade-offs, and measurable outcomes in a realistic interview setting. A strong answer for Walk through your resume and impacts states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Behavioral & LeadershipTechnical Screen
  • ExaHardMachine Learning Engineer
    Debug a PyTorch Contrastive Loss

    Repair a PyTorch contrastive loss whose matrix multiplication contracts incompatible dimensions instead of producing pairwise scores. Validate aligned rank-two tensors and temperature, create the correct batch-by-batch logits, preserve gradients, and handle low-precision numerical stability.

    Machine LearningTechnical Screen
  • ExaHardMachine Learning Engineer
    Design a Streaming Percentile Estimator

    Design a streaming percentile estimator without storing every observation, and define rank error precisely. Compare a deterministic single-stream summary with t-digest-style centroids across memory, update cost, duplicates, skew, tail accuracy, and distributed merge limitations.

    Statistics & MathTechnical Screen
  • ExoduspointMediumSoftware Engineer
    Find minimal time for four people crossing

    This question evaluates algorithmic problem-solving and combinatorial optimization skills, focusing on reasoning about constrained pairing, state-space search, and minimizing total time under movement constraints.

    Coding & AlgorithmsTechnical Screen
  • ExpediaMediumData Scientist
    Audit and onboard unfamiliar datasets safely

    This question evaluates a data scientist's competency in dataset discovery, schema and key verification, profiling for distributions/missingness/timezones/currencies, duplicate and join-inflation detection, event-sequence validation, accurate metric computation, and the design of data-quality tests/data contracts within SQL/Python workflows.

    Data Manipulation (SQL/Python)Onsite
  • ExpediaHardData Scientist
    Choose KPIs and prove impact with experiments

    This question evaluates a data scientist's competency in KPI engineering, causal inference, experiment design, metric validation, and multi-touch attribution within the Analytics & Experimentation domain and is focused on profit-oriented search ranking.

    Analytics & ExperimentationOnsite
  • ExpediaMediumSoftware Engineer
    Consolidate Three Partner APIs into a Query Service

    This problem tests your ability to design a robust middleware layer that abstracts heterogeneous downstream APIs into a unified, reliable, and performant service.

    System DesignOnsiteAPI AggregationMiddlewareMicroservices
  • ExpediaHardSoftware Engineer
    Describe when you distrusted a colleague

    This question evaluates interpersonal judgment, trust assessment, conflict resolution, accountability, and leadership skills in a software engineering context, categorized under Behavioral & Leadership.

    Behavioral & LeadershipTechnical Screen
  • ExpediaHardSoftware Engineer
    Design a listing connectivity ingestion service

    This question evaluates a candidate's ability to design scalable, reliable REST APIs and distributed ingestion pipelines, testing competencies in API specification, idempotency, authentication/authorization, asynchronous processing, observability, and integration with downstream validation services.

    System DesignTechnical Screen
  • ExpediaHardSoftware Engineer
    Design a natural-disaster notification system

    This problem tests your ability to design a high-throughput, geo-aware notification system that must deliver time-sensitive alerts to users based on their current or planned location during natural disasters.

    System DesignOnsiteGeospatialScalabilityEvent-Driven
  • ExpediaHardSoftware Engineer
    Design an employee directory with reporting queries

    This question tests the ability to design a scalable hierarchical data structure, select appropriate storage backends for recursive queries, and handle write-heavy concurrent updates to organizational charts.

    System DesignOnsiteDatabase ModelingHierarchical DataAPI Design
  • ExpediaMediumSoftware Engineer
    Find a Canonical Shortest Round Trip Through Flights

    Find the shortest directed round trip starting and ending at a given airport, breaking ties lexicographically.

    Coding & AlgorithmsOnsitegraphbfsshortest-path