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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
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- 11
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Showing 811–840 of 4616 results
- BnpEasyData ScientistWhat are linear regression assumptions?
Assesses understanding of the assumptions underlying ordinary least squares linear regression and the application of diagnostic methods to ensure unbiased parameter estimates and valid statistical inference.
Machine LearningTechnical Screen - BnsfMediumSoftware EngineerImplement a rail freight quote API service layer and scale it for slow dependencies
Given a REST API requirements document for a rail freight quote endpoint that depends on other services and a database, write the service-layer logic. Then design an architecture that keeps the endpoint fast and reliable under heavy traffic when its dependencies are slow, covering caching, timeouts, fallbacks and asynchronous quotes.
Software Engineering FundamentalsTechnical Screen - 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 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 - 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 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 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 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 ScientistQuery top spenders and 7-day growth
This question evaluates proficiency in SQL data manipulation, including aggregations, date-range filtering, joins, window functions for ranking and tie-breaking, and computing revenue shares and growth rates within a relational schema.
Data Manipulation (SQL/Python)Technical Screen - Boston Consulting GroupHardData ScientistReduce overfitting under constraints
This question evaluates a candidate's competency in machine learning for mitigating overfitting in tabular regression under production latency constraints, testing knowledge of regularization, model complexity control, feature engineering, validation strategies, and experimental design.
Machine LearningTechnical Screen - Boston Consulting GroupMediumData ScientistSummarize impact and lessons from your resume
This question evaluates a data scientist's ability to communicate measurable impact, design and track metrics, manage stakeholders and conflicts, and demonstrate accountability through concrete project examples, testing Behavioral & Leadership competencies specific to the Data Scientist role.
Behavioral & LeadershipTechnical Screen - Boston Consulting GroupMediumData ScientistTransform messy transactions with pandas
This question evaluates proficiency in large-scale data manipulation and feature engineering using pandas, covering timestamp normalization across time zones, deduplication and last-write-wins semantics, data validation, memory-efficient aggregation, rolling-window statistics, and top-k categorical extraction for merchant categories.
Data Manipulation (SQL/Python)Technical Screen - Boston Consulting GroupMediumData ScientistVisualize and Clean SKU Sales Data for Outliers
This question evaluates data manipulation and exploratory data analysis skills, including aggregation, outlier detection (IQR/Z-score) and visualization using Python libraries such as pandas and matplotlib/seaborn.
Data Manipulation (SQL/Python)Technical Screen - BrexMediumSoftware EngineerAnswer Behavioral Questions
This question evaluates a candidate's behavioral competencies such as ownership, communication under pressure, conflict resolution, accountability, and motivation reflected in long-term goals.
Behavioral & LeadershipTechnical Screen - BrexMediumSoftware EngineerBuild AI-Assisted Full-Stack Transactions App
This question evaluates full‑stack engineering competencies including API design, data persistence, input validation, transactional integrity for monetary data, frontend-backend integration, automated testing, and developer documentation.
System DesignTechnical Screen - BrexMediumSoftware EngineerBuild a React color multi-select dropdown UI
This question evaluates front-end React skills including component architecture, state management, data-driven rendering, accessibility considerations, and performance trade-offs involved in implementing a multi-select dropdown that presents selected colors' properties.
Software Engineering FundamentalsTechnical Screen - BrexMediumSoftware EngineerDebug and Explain Fixes
This question evaluates a candidate's debugging and root-cause analysis skills, familiarity with unit testing and regression prevention, and ability to modify a small codebase to fix defects within the coding and algorithms domain.
Coding & AlgorithmsTechnical Screen - BrexHardSoftware EngineerDesign Points-from-Transactions Service
This question evaluates system design and distributed-systems competency, focusing on transaction processing, idempotency and deduplication, monetary precision and rounding, consistency models, data modeling, and operational controls like observability and fraud prevention.
System DesignTechnical Screen - BrexEasySoftware EngineerImplement discounted card purchases
This question evaluates implementation-level skills in resource accounting and state management, specifically handling gem-cost mappings, per-color discounts, bounded arithmetic, and transactional updates to player state.
Coding & AlgorithmsTechnical Screen - BrexMediumSoftware EngineerSplendor-Style Card Purchases with Gem Costs, Color Discounts and Concurrent Buys
Model a Splendor-style card game in code: check whether a player's five-color gem inventory can afford a card, make an all-or-nothing purchase, and apply discounts earned from cards already owned. A follow-up asks how to keep one player's simultaneous purchase requests safe and consistent.
Software Engineering FundamentalsTechnical Screen - BridgeMediumSoftware EngineerDesign Minesweeper and Optimize Click Performance
This question evaluates a candidate's competence in data structures, graph traversal and flood-fill concepts, complexity analysis, and scalable system design for sparse board representations.
Coding & AlgorithmsTechnical Screen - BridgeMediumSoftware EngineerDesign signup and login service
This question evaluates understanding of authentication system design, secure password storage practices, API endpoint and request/response modeling, database schema design, and session or token-based login state management.
System DesignTechnical Screen - BridgeMediumSoftware EngineerImplement a Stepped Iterator
Design and implement a stepped iterator class that wraps an underlying iterator or sequence, advancing by a configurable step size on each call. This tests iterator design, state management, invariant preservation, and edge-case handling.
Software Engineering FundamentalsTechnical ScreenDesignIteratorsData Structures
Bnp
Booking.com
Boston Consulting Group
Brex