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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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- 8
- Languages
Showing 2461–2490 of 3640 results
- New RelicMediumBackend EngineerDesign a Kafka Consumer Service That Groups Trace Events by Trace ID
Design a distributed service that consumes trace events from Kafka, groups every event sharing a trace ID, and hands each complete trace to an existing processing function. Covers partitioning, in-memory versus external state, deciding when a trace is complete, and traces that stay open for hours.
System DesignOnsite - New RelicMediumBackend EngineerLongest Strictly Increasing Path in a Grid with Four-Directional Moves
Given an integer matrix, find the number of cells on the longest path whose values strictly increase, moving only up, down, left, or right with no diagonal steps and no wrap-around at the edges. Tests grid search and the ability to turn a working first solution into an efficient one.
Coding & AlgorithmsOnsite - NooksMediumSoftware EngineerHow would you throttle a crawler?
This question evaluates competency in scalable distributed system design, including rate limiting, request scheduling, concurrency control, fault tolerance, backoff/retry strategies, deduplication, and observability for networked crawlers.
System DesignOnsite - NooksMediumSoftware EngineerImplement a BFS web crawler
This question evaluates proficiency in breadth-first search and graph traversal concepts applied to web crawling, including handling duplicate links, hostname filtering, and tracking visited URLs.
Coding & AlgorithmsOnsite - NotionMediumSoftware EngineerDesign a Shared Calendar Service
This problem tests the ability to design a scalable shared calendar system with support for recurring events, granular permission models, and notification scheduling.
System DesignOnsiteDatabase SchemaScalabilityAsynchronous Processing - NotionMediumSoftware EngineerDesign a Todo List Object Model
Tests object-oriented design, domain modeling, and API design skills by implementing an extensible, hierarchical Todo list model with task dependency management and filtering.
Software Engineering FundamentalsOnsiteObject-Oriented DesignAPI DesignDesign Patterns - NotionMediumData EngineerExplain impact and partnership
This question evaluates a Data Engineer's behavioral and leadership competencies, including ownership, cross-functional collaboration with data scientists and partners, stakeholder communication, problem framing, impact measurement, and responsiveness to managerial feedback, and is categorized under Behavioral & Leadership.
Behavioral & LeadershipOnsite - NotionMediumSoftware EngineerFind Top Errors in Time Window
This problem tests your ability to process streaming log data within a sliding time window, aggregate frequencies using hash maps, and implement custom sorting logic.
Coding & AlgorithmsOnsiteHash MapSortingData Processing - NubankMediumSoftware EngineerDesign Chargeback Ingestion and CSV Delivery
Tests the ability to design an end-to-end financial transaction pipeline that ingests, deduplicates, and validates chargeback events, then reliably batches and delivers immutable CSV files to external card schemes via SFTP.
System DesignOnsiteFintechBatch ProcessingEvent-Driven - NubankEasySoftware EngineerDesign a chargeback ingestion and export system
This question assesses the ability to design a distributed system that reliably ingests high-volume transaction records and prepares them for periodic downstream delivery while ensuring data consistency and auditability.
System DesignOnsiteDistributed SystemsIdempotencyData Pipelines - NuroHardSoftware EngineerCompare Locks and MVCC in a Versioned Store
Tests deep understanding of concurrency control paradigms by comparing pessimistic locking against Multi-Version Concurrency Control (MVCC) in a versioned key–value storage engine, focusing on version lifecycle, garbage collection, and read/write trade-offs.
Software Engineering FundamentalsOnsiteStorage EnginesConcurrency ControlMVCC - NuroHardBackend EngineerDesign Webhooks and Metric Aggregation
Design a webhook delivery platform and vehicle telemetry aggregation system. The solution covers multi-tenant subscriptions, at-least-once delivery, retries, signing, DLQs, endpoint isolation, high-volume ingestion, stream processing, raw storage, rollups, alerting, late events, and downsampling.
System DesignOnsite - NuroHardSoftware EngineerDesign a Shared Distributed ML Training Platform
Design a multi-tenant distributed machine learning training platform that orchestrates GPU clusters, enforces team quotas, guarantees gang scheduling, and handles node-level checkpointing and recovery.
ML System DesignOnsiteml-system-designdistributed-systemscluster-management - NuroHardSoftware EngineerExplain Project Scope, Ownership, and Technical Challenges
Assess a candidate's ability to articulate end-to-end technical leadership, architectural decision-making, and deep problem-solving on a complex engineering project. Evaluates clear communication of personal ownership, rigorous validation methods, and retrospective insights.
Behavioral & LeadershipOnsiteBehavioralTechnical LeadershipArchitecture - NuroHardBackend EngineerImplement BFS and a Job Scheduler
Solve grid reveal with BFS and design a thread-safe periodic job scheduler. The solution covers Minesweeper-style expansion, queue processing, priority-queue scheduling, locks, worker pools, cancellation, duplicate prevention, long-running tasks, clock drift, and backpressure.
Coding & AlgorithmsOnsite - NuroHardSoftware EngineerImplement a thread-safe periodic job scheduler
Implement a thread-safe periodic job scheduler evaluates engineering fundamentals, trade-offs, examples, pitfalls, and operational implications in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Software Engineering FundamentalsOnsite - NuroHardSoftware EngineerSchedule CPU and GPU Video Processing
Design a distributed heterogeneous batch-processing system to schedule and execute multi-stage video pipelines across CPU and GPU worker clusters with fault tolerance, backpressure, and cost-efficient resource management.
System DesignOnsitesystem-designdistributed-systemsbatch-processing - NuroHardSoftware EngineerSearch Large Vehicle Records with Bounded Memory
Design a petabyte-scale search engine for autonomous vehicle records supporting multidimensional range queries, bounded-memory query execution, and stable streaming pagination.
System DesignOnsitesystem-designdistributed-systemsbig-data - OktaMediumBackend EngineerBuild and Review a Configurable Node.js Token-Bucket Rate Limiter
Implement a configurable Node.js Express token-bucket rate limiter with monotonic refill, HTTP 429 responses, code-review reasoning, and multi-instance limits.
Software Engineering FundamentalsOnsite - OktaMediumBackend EngineerDesign Cross-Domain SSO and OIDC Access to Third-Party Tools
Design cross-domain SSO with OIDC authorization-code flow, separate site sessions, secure account linking, third-party federation, and delegated API authorization.
System DesignOnsite - OktaMediumBackend EngineerDesign Single Sign-On Across Two Acquired Sites With OIDC Federation
Design cross-domain single sign-on after one company acquires a second site on a different domain, then extend it to many sites and to delegated API access for third-party tools, covering the authorization-code flow, session separation, and the authentication-versus-authorization distinction.
System DesignOnsitesystem-designauthenticationoidc - OktaMediumBackend EngineerRepair an Express Authentication Endpoint Without Blocking the Event Loop
Repair an Express authentication endpoint with input validation, asynchronous bcrypt, safe errors, correct HTTP status codes, and event-loop-aware resource controls.
Software Engineering FundamentalsOnsite - OmnissaMediumSoftware EngineerAlternate Odd and Even Numbers with Two Threads
This problem tests knowledge of thread synchronization using locks and condition variables to enforce a specific execution order between two concurrent processes.
Coding & AlgorithmsOnsiteConcurrencyMultithreadingSynchronization - OmnissaMediumSoftware EngineerCheck Whether a Singly Linked List Is a Palindrome
Tests the ability to determine if a singly linked list is a palindrome in O(n) time and O(1) auxiliary space using two pointers and in-place list reversal.
Coding & AlgorithmsOnsiteLinked ListTwo PointersIn-Place Reversal - OmnissaMediumSoftware EngineerFind the Celebrity from a Knows Matrix
This problem tests the ability to solve a search problem in O(N) time by utilizing the transitive and exclusionary properties of the 'knows' relationship to eliminate candidates.
Coding & AlgorithmsOnsiteArraysTwo PointersAlgorithms - OmnissaMediumSoftware EngineerFind the Maximum Sum of a Contiguous Subarray
This problem tests the ability to implement Kadane's algorithm to find the maximum sum of a contiguous subarray, specifically focusing on handling negative integers and maintaining optimal time and space complexity.
Coding & AlgorithmsOnsiteArraysDynamic ProgrammingKadane's Algorithm - OmnissaMediumSoftware EngineerPresent a Project Architecture and Your Hardest Technical Decision
This question evaluates your ability to articulate complex system architectures clearly, explain key technical trade-offs, demonstrate personal ownership, and evaluate the long-term impact of architectural decisions.
Behavioral & LeadershipOnsiteSystem ArchitectureTechnical LeadershipTrade-Off Analysis - OmnissaMediumSoftware EngineerPrioritize Two Important Tasks with Competing Deadlines
Assesses how an engineer navigates conflicting priorities, evaluates business versus technical trade-offs, communicates transparently with stakeholders, and executes under tight timelines.
Behavioral & LeadershipOnsiteBehavioralPrioritizationStakeholder Management - OmnissaMediumSoftware EngineerRepeatedly Remove Adjacent Equal Characters
This problem tests your ability to handle recursive reduction patterns in a string using a stack-based approach to achieve linear time complexity.
Coding & AlgorithmsOnsiteStackStringGreedy - OneMain FinancialMediumData ScientistCalculate Profit-Maximizing Price and Validate with Additional Data
Evaluates profit-maximizing pricing from demand curves, marginal revenue, marginal cost, and validation data. Strong answers derive optimal price and quantity, provide examples, and request experiments or elasticity evidence.
Analytics & ExperimentationOnsite
Notion
Nuro
Okta
OneMain Financial