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Backend Engineer 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 61–90 of 91 results
- RilletMediumBackend EngineerDistribute Annual Revenue Across Twelve Months
This problem tests logic, integer arithmetic, and edge-case handling by requiring the distribution of a total sum into equal parts while managing remainders without using floating-point numbers.
Coding & AlgorithmsTechnical ScreenAlgorithmsInteger ArithmeticData Manipulation - RipplingMediumBackend EngineerDesign a News Aggregator That Builds Personalized Feeds from Publisher APIs
System design question on building a news aggregator that polls many publisher APIs, stores only article metadata, and serves each user a paginated feed from the publishers and categories they follow. It tests polling schedules and stop conditions, rate-limit and outage handling, feed merging with deduplication, stable cursors, and bounded storage.
System DesignOnsite - RipplingMediumBackend EngineerProcess a Task List: Deduplicate, Drop Completed, Sort by Priority, and Nest Subtasks
Senior backend coding question: process a batch of scheduler tasks by removing duplicates on description and due date, dropping completed tasks, sorting by priority, and placing each subtask directly after its parent. It tests clarifying ambiguous policies, orphan and cycle handling, O(n log n) design, and verified use of an AI coding assistant.
Software Engineering FundamentalsOnsite - RipplingMediumBackend EngineerSenior Backend Hiring Manager Deep Dive: Idempotency, SLAs, Changed Decisions, and Pushback
Senior backend hiring manager round covering your proudest project with deep dives on idempotency and SLA definition and monitoring, a technical decision you reversed, a design a colleague challenged, and company-specific motivation. It tests ownership, technical depth, judgment under disagreement, and honest self-reflection.
Behavioral & LeadershipOnsite - RobinhoodMediumBackend EngineerCount and Rank Words in a Paragraph
This problem tests string manipulation, hash map usage for frequency counting, and custom sorting logic for deterministic ordering.
Coding & AlgorithmsTechnical ScreenStringsHash MapSorting - RobinhoodMediumBackend EngineerCritique a Recent Engineering Project and Explain What You Would Redo
Prepare a candid deep dive on a recent engineering project, including personal ownership, a consequential technical decision, and observed outcomes. Identify a real weakness, trace its cause, and explain what you would redesign today.
Behavioral & LeadershipTechnical Screen - RobinhoodMediumBackend EngineerDeep-Dive a Distributed Service Project
This question assesses a candidate's ability to articulate the architecture, constraints, and operational challenges of a distributed system they previously owned, while demonstrating clarity in personal impact and technical decision-making.
Behavioral & LeadershipTechnical ScreenSystem DesignDistributed SystemsCommunication - RobinhoodMediumBackend EngineerScale Word-Frequency Processing Beyond One Machine
This question tests the ability to design a distributed data processing pipeline that handles large-scale text files by balancing memory constraints, horizontal scalability, and data integrity.
System DesignTechnical ScreenDistributed SystemsMapReduceScalability - RokuMediumBackend EngineerDesign a high-throughput ad exchange
This problem tests your ability to design a low-latency, high-throughput distributed system capable of managing real-time bidding (RTB) auctions for streaming video advertisements.
System DesignOnsiteDistributed SystemsLow LatencyHigh Throughput - RokuMediumBackend EngineerExplain concurrency and distributed fundamentals
This question tests fundamental knowledge of thread-safe collections in Java and core distributed systems architectural patterns, specifically partitioning strategies.
Software Engineering FundamentalsOnsiteJavaConcurrencyDistributed Systems - SalesforceEasyBackend EngineerDesign a Chat Analytics Backend
This question evaluates a candidate's competence in designing large-scale analytics backends, covering data ingestion, event and metric schemas, near-real-time and historical analytics, metric computation and slicing, data freshness and deduplication, privacy and access control, operational monitoring, and the API/query layer.
System DesignOnsite - Scale AIEasyBackend EngineerBuild a CSV-to-JSON Classification Service
Implement a resilient data pipeline service that parses CSV records, enriches them using an external classification client with validation and retries, and writes ordered, structured JSON Lines output safely.
Software Engineering FundamentalsOnsiteData PipelinesConcurrencyError Handling - Scale AIEasyBackend EngineerDesign a Durable Task Scheduling Service
Design a resilient, distributed task scheduling service that decouples scheduling from execution, supporting both delayed one-time tasks and recurring cron jobs with strong durability and at-least-once delivery.
System DesignOnsiteDistributed SystemsTask SchedulerConcurrency - SpotifyMediumBackend EngineerA Time You Lifted Your Team's Morale and Energy
A Spotify behavioral question asking for a time you brought positivity to your team. It tests whether you notice morale problems, take specific and genuine actions to address them, stay candid about real issues, and can show the effect on the team.
Behavioral & LeadershipOnsite - SpotifyMediumBackend EngineerDesign a Public Upload and Hosting Service for Playlist Cover Images
A Spotify system design question: design a service that lets users upload, replace and remove a public cover image for their playlists, served to the app and to third-party embeds. Follow-ups cover how an auditor would review image changes and how upload and processing failures are handled.
System DesignOnsite - SpotifyMediumBackend EngineerHow You Use AI Tools as an Engineer and Drive Their Adoption on Your Team
A Spotify behavioral question in two parts: how you use AI tools in your engineering work and side projects, and how you have pushed for AI adoption on your team. It tests judgment about AI output, verification habits, data safety, and influencing teammates.
Behavioral & LeadershipOnsite - SpotifyMediumBackend EngineerLongest Contiguous Stretch of Distinct Characters in a String
A Spotify backend technical-screen coding problem: given a string, find the length of the longest contiguous substring in which no character repeats. It tests careful string scanning, linear-time reasoning, and edge cases such as case sensitivity, ties and empty input.
Coding & AlgorithmsTechnical Screen - SpotifyMediumBackend EngineerOn-Call Case Study: Debugging a Misbehaving Production Server
A Spotify on-call case study: as the engineer paged about a misbehaving production server, investigate by asking for metrics, logs and command output. It tests triage, impact assessment, systematic host and service diagnostics, mitigation trade-offs and incident follow-through.
Software Engineering FundamentalsOnsite - SpotifyMediumBackend EngineerStaying Productive When Project Requirements Were Unclear or Kept Changing
A Spotify behavioral question about a project with unclear or constantly changing requirements, asking how you adapted and stayed productive. It tests how you reduce ambiguity, structure work to absorb change, communicate the cost of churn, and reflect on the outcome.
Behavioral & LeadershipOther - SpotifyMediumBackend EngineerVisit-Pattern Counter: Multi-Input Runtime Analysis and Production Hardening
A Spotify backend coding follow-up: for a function that finds the three-website visit pattern followed by the most distinct users, analyze time and memory using separate input dimensions such as records, users, longest per-user history and distinct sites. It also asks which functional and style changes the code needs before it ships in production.
Software Engineering FundamentalsOnsite - TargetMediumBackend EngineerFind the Closest Candidate String by Edit Distance
This problem tests the implementation of the Levenshtein distance algorithm (Edit Distance) and the ability to manage tie-breaking logic when comparing multiple strings against a query.
Coding & AlgorithmsOnline AssessmentDynamic ProgrammingStringsOptimization - TargetMediumBackend EngineerImplement a Synchronized First-Available Seat Allocator
This problem tests your ability to design a thread-safe allocator that manages a finite resource pool under high concurrency, focusing on atomic updates and race condition prevention.
Software Engineering FundamentalsOnline AssessmentConcurrencyAtomic OperationsThread Safety - TeslaMediumBackend EngineerCompute time to burn tree
This question evaluates proficiency with tree algorithms, distance computation, and propagation modeling, testing the ability to reason about how a process spreads across parent-child relationships in a tree.
Coding & AlgorithmsOnsite - TeslaMediumBackend EngineerDescribe conflict and proudest work
This question evaluates interpersonal conflict resolution, collaboration, ownership, and impact-communication skills within the Backend Engineer role and falls under the Behavioral & Leadership domain.
Behavioral & LeadershipOnsite - TeslaMediumBackend EngineerDesign booking and settlement systems
This question evaluates backend system design competencies such as concurrency control, transactional integrity, reconciliation, file ingestion and processing, idempotency, API design, and operational reliability.
System DesignOnsite - TeslaMediumBackend EngineerExplain reliability and runtime fundamentals
This question evaluates understanding of reliability and runtime fundamentals in backend engineering, covering competencies such as fault tolerance, end-to-end request lifecycles, API gateway degradation, storage engine selection for search, and the distinction between compilers and interpreters.
Software Engineering FundamentalsOnsite - UberMediumBackend EngineerReplace Dashes With Nearest Letters
This problem tests your ability to perform a multi-source shortest path search on a grid to determine the influence of characters on empty spaces, using Manhattan distance and lexicographical tie-breaking.
Coding & AlgorithmsTechnical ScreenBFSGridGraph - ValonMediumBackend EngineerDesign Correct Stateful Services for Irregular Financial Events
A systems-design interview about correct stateful processing for sparse records, out-of-order loan events, investor payment allocation, and authenticated APIs. It emphasizes idempotency, ledgers, exact arithmetic, recovery, and auditability.
System DesignOnsite - ZipHQMediumBackend EngineerFind Bugs in an LRU Cache
Identify behavioral bugs in a Java-based LRU Cache implementation using LinkedHashMap, write minimal failing tests, and provide the corrected code.
Software Engineering FundamentalsTechnical Screenjavadata-structuresdebugging - ZooxMediumBackend EngineerDesign Real-Time Vehicle Location Tracking
Design a high-throughput, low-latency telemetry ingestion and distribution system that streams autonomous vehicle coordinates to client dashboards and rider apps.
System DesignTechnical ScreenReal-TimeGeospatialWebSockets
Rippling
Robinhood
Salesforce
Scale AI
Spotify
Tesla
Uber
ZipHQ
Zoox