practice a little every day, paws crossed ♡
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 1681–1710 of 9403 results
- BnsfHardSoftware EngineerMaximize Valid Trains from Shared Equipment
Form the maximum number of valid trains from a shared pool of locomotives and railcars, breaking ties by maximizing total railcar length.
Coding & AlgorithmsOnsiteBitmask DPBacktrackingBranch and Bound - BnsfMediumSoftware EngineerMinimize Car Removals for a Two-Car Bridge
Determine the minimum number of cars to remove from a queue so that no single retained car nor any adjacent retained pair exceeds a bridge's weight limit.
Coding & AlgorithmsOnline AssessmentDynamic ProgrammingBinary Indexed TreeSegment Tree - BobyardMediumSoftware EngineerBuild Nested Comments from Parent References
This problem tests your ability to handle tree data structures, pointer manipulation, and graph validation while processing unordered flat data.
Software Engineering FundamentalsTechnical ScreenTreesGraphsHash Maps - BobyardMediumSoftware EngineerDesign a client-side comment system
This question evaluates front-end engineering competencies including client-side data modeling, state management, UI behavior for nested comment trees, sorting/filtering semantics, and persistence using localStorage.
System DesignTechnical Screen - BobyardMediumSoftware EngineerDesign comments and async image generation
This question evaluates full-stack system-design competencies, including CRUD API and data-model design for sortable queries with persisted user preferences, frontend-backend synchronization, and asynchronous long-running job orchestration, status/result APIs, and UI ordering for image generation; it falls under the System Design category and tests a mix of conceptual architectural reasoning and practical application design. It is commonly asked because it probes the ability to balance scalability, consistency, user experience, and fault-tolerant asynchronous processing when designing end-to-end systems that must handle persistence, ordering guarantees, and long-running background work.
System DesignTechnical Screen - BobyardMediumSoftware EngineerHow do you debug slowness and bugs?
This question evaluates troubleshooting and incident-response competencies, including performance debugging, root-cause analysis, severity assessment, mitigation and impact reduction, stakeholder communication, and safe deployment practices for web applications.
Software Engineering FundamentalsTechnical Screen - BobyardMediumSoftware EngineerImplement comment sorting and nesting
This question evaluates skills in frontend data handling and UI behavior, including implementing sortable lists, maintaining user-selected sort field and direction across refreshes, constructing nested comment trees from flat parentId references, and filtering content while preserving descendant visibility.
Coding & AlgorithmsTechnical Screen - BoeingEasySoftware EngineerCompute unique-substring length and first unique index
This problem tests your ability to manage character frequency counts and sliding window techniques to identify properties of unique substrings and characters.
Coding & AlgorithmsTechnical ScreenStringSliding WindowHash Map - BoeingEasySoftware EngineerExplain AWS access control and frontend typing
This question tests fundamental knowledge of cloud security primitives in AWS and modern frontend development patterns, specifically focusing on secure data access and robust TypeScript architecture.
Software Engineering FundamentalsTechnical ScreenAWSS3IAM - Booking.comMediumSoftware EngineerCompare heap, stack, Protobuf, gRPC, SQL, CI/CD
Compare heap, stack, Protobuf, gRPC, SQL, CI/CD 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 - Booking.comMediumSoftware EngineerDesign a Real-Time Logging System
This question evaluates a candidate's competency in designing scalable, low-latency telemetry and logging systems, covering distributed systems architecture, ingestion pipelines, data modeling, real-time querying, reliability, backpressure, partitioning, indexing, retention, and operational trade-offs.
System DesignOnsite - Booking.comMediumSoftware EngineerDesign an AI-Assisted Development Workflow
Design an end-to-end, safe AI-assisted development workflow incorporating bounded task scopes, structured agent skills, deterministic guardrail hooks, and automated review gates.
Software Engineering FundamentalsTechnical ScreenAI WorkflowsDeveloper ToolingSystem Design - Booking.comMediumSoftware EngineerMatch Bookings to Payments
This question evaluates skill in matching records across unsorted collections, focusing on data structures, aggregation and handling one-to-one and one-to-many relationships between bookings and payments.
Coding & AlgorithmsOnsite - Booking.comMediumSoftware EngineerSolve three OA coding questions
This 90-minute assessment evaluates algorithmic problem-solving skills including string manipulation and grouping for anagram detection, digit-level reasoning for one-swap maximization, and text tokenization with aggregation and ranking for sentiment-based scoring.
Coding & AlgorithmsOnline Assessment - Boston Consulting GroupMediumData ScientistAchieve 0.95 precision via thresholding
This question evaluates probabilistic classifier calibration, threshold selection to achieve a target precision, handling severe class imbalance, and precision–recall based evaluation metrics.
Machine LearningOnline Assessment - Boston Consulting GroupMediumData ScientistAnalyze Python Functions: Improve Readability and Efficiency
This interview question evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer for Analyze Python Functions: Improve Readability and Efficiency states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsTechnical Screen - Boston Consulting GroupEasySoftware EngineerAnswer common behavioral questions using STAR
This question evaluates interpersonal communication, self-reflection, problem-solving, teamwork, and leadership competencies by prompting concrete examples of prior behavior and decision-making in workplace situations.
Behavioral & LeadershipHR Screen - Boston Consulting GroupMediumData ScientistBuild a leak-free sklearn pipeline
This problem tests the ability to build a robust scikit-learn pipeline that prevents data leakage during preprocessing and hyperparameter tuning while handling class imbalance.
Machine LearningOnline Assessmentscikit-learndata-leakagepipelines - Boston Consulting GroupMediumData ScientistBuild and evaluate imbalanced binary classifier
This question evaluates a data scientist's skills in building reproducible machine learning pipelines for imbalanced binary classification, covering temporal splitting to avoid leakage, class imbalance handling, feature preprocessing, probability calibration, threshold selection, and monitoring for calibration drift.
Machine LearningOnline Assessment - Boston Consulting GroupEasyData ScientistCalculate Probability and Statistics for Dice Roll Outcomes
This interview question evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer for Calculate Probability and Statistics for Dice Roll Outcomes states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Statistics & MathOnline Assessment - Boston Consulting GroupEasyData ScientistCalculate Probability of Heads and Red Balls Drawing
This interview question evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer for Calculate Probability of Heads and Red Balls Drawing states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Statistics & MathOnline Assessment - Boston Consulting GroupMediumData ScientistCompute posterior and predictive coin probabilities
This question evaluates Bayesian inference and probabilistic reasoning, focusing on posterior updating, posterior predictive probability, and the conditional expectation of a stopping time given observed outcomes.
Statistics & MathOnline Assessment - Boston Consulting GroupMediumData ScientistDesign and sample for credit default prediction
This question evaluates a data scientist's competencies in imbalanced binary classification, temporal label definition and leakage detection, sampling and calibration under prior-probability shift, metric and operating-point selection, cost-sensitive decision rules, time-based validation and monitoring, and fairness and operational guardrails.
Machine LearningTechnical Screen - Boston Consulting GroupHardData ScientistDetect Data Leakage in Supervised Learning Pipelines
This interview question evaluates core ML concepts, assumptions, math intuition, training/evaluation trade-offs, and practical failure modes in a realistic interview setting. A strong answer for Detect Data Leakage in Supervised Learning Pipelines states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Machine LearningOnline Assessment - Boston Consulting GroupEasySoftware EngineerDiscuss languages, packages, and tools you know
This question evaluates familiarity with programming languages, libraries/frameworks, and development tooling, along with the ability to apply a technology stack to deliver measurable impact.
Software Engineering FundamentalsHR Screen - Boston Consulting GroupMediumData ScientistIdentify Causes and Solutions for Fashion Profit Decline
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 Identify Causes and Solutions for Fashion Profit Decline states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Analytics & ExperimentationTechnical Screen - Boston Consulting GroupMediumData ScientistImprove Model Generalization with Cross-Validation and Feature Engineering
This interview question evaluates core ML concepts, assumptions, math intuition, training/evaluation trade-offs, and practical failure modes in a realistic interview setting. A strong answer for Improve Model Generalization with Cross-Validation and Feature Engineering states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Machine LearningOnline Assessment - Boston Consulting GroupMediumData ScientistManipulate and merge DataFrames correctly
This question evaluates proficiency in pandas-based data manipulation and merging, covering join validation, vectorized revenue and discount calculations, missing-value imputation, groupby/transform usage, dtype setting, and avoiding SettingWithCopy issues.
Data Manipulation (SQL/Python)Technical Screen - Boston Consulting GroupMediumData ScientistMerge and Clean Customer Order Data for Analysis
This question evaluates proficiency in data manipulation with pandas and SQL concepts, focusing on dataset merging, missing-value handling, and computing derived aggregate columns such as total_spent.
Data Manipulation (SQL/Python)Online Assessment - Boston Consulting GroupMediumData ScientistMerge and Concatenate Inconsistent Order Files with Pandas
This question evaluates proficiency with pandas-based data manipulation, including schema alignment, column renaming, type casting, and vertical concatenation when merging CSV files.
Data Manipulation (SQL/Python)Online Assessment
Booking.com
Boston Consulting Group