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Software 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 31–60 of 2336 results
- AirbnbMediumSoftware EngineerAllocate an Order from the Oldest Inventory Batches
Implement a function to allocate an order across inventory batches using FIFO (oldest timestamp first, with batch ID tie-breaker), returning allocation details and any unfilled quantity without mutating the input.
Coding & AlgorithmsOnsitesortinggreedyarrays - AirbnbMediumSoftware EngineerAllocate refund across payments
This question evaluates algorithm design and data-structure selection skills, focusing on greedy allocation, ordering by priority and recency, aggregation of transaction amounts, and analysis of time complexity.
Coding & AlgorithmsOnsite - AirbnbMediumSoftware EngineerCompute board-game score from regions
This problem tests your ability to identify connected components in a 2D grid using graph traversal (BFS/DFS) and aggregate properties associated with those components.
Coding & AlgorithmsOnsiteGraph TraversalBFSDFS - AirbnbHardSoftware EngineerCount Consecutive Positive Integer Sums
Count representations of a positive integer as one or more consecutive positive integers, including the one-term representation. Derive the arithmetic condition for each sequence length and use a square-root bound rather than testing every possible starting value.
Coding & AlgorithmsOnsite - AirbnbMediumSoftware EngineerDescribe a cross-functional project you’re proud of
This question evaluates cross-functional collaboration, leadership, stakeholder alignment, conflict resolution, project ownership, and the ability to articulate technical and product decisions along with measurable impact.
Behavioral & LeadershipOnsite - AirbnbMediumSoftware EngineerDescribe a flagship project’s architecture and tradeoffs
This question evaluates leadership and ownership along with system architecture and trade-off analysis, assessing competencies in end-to-end technical design, stakeholder communication, implementation decisions, and metrics-driven impact.
Behavioral & LeadershipOnsite - AirbnbMediumSoftware EngineerDesign a Reliable Scheduler for Payment Jobs
Tests candidate's ability to design a mission-critical, fault-tolerant job scheduler for payment processing, focusing on lease claiming, idempotency, race condition handling, and reconciliation.
System DesignOnsitesystem-designdistributed-systemspayments - AirbnbMediumSoftware EngineerDesign a booking system
This question tests the ability to design a distributed reservation system that handles high concurrency, prevents double-booking, and ensures data consistency at scale.
System DesignOnsiteConcurrencyDatabaseDistributed Systems - AirbnbHardSoftware EngineerDesign a dynamic rental pricing system
This question evaluates skills in production machine learning system design for pricing, including problem formulation, data and feature engineering, modeling and uncertainty management, online inference and scalability, experimentation and guardrails, and considerations like fairness and cold-start handling.
ML System DesignOnsite - AirbnbHardSoftware EngineerDesign a group chat system
Airbnb's onsite system design round asks you to design the backend for a real-time group chat and messaging system: 1:1 and group conversations, near-real-time delivery, accurate unread counts, and full paginated history at roughly 1B messages a day and 5M concurrent connections. A complete answer covers the guarantees, APIs, data model and partitioning, write path and ordering, WebSocket fan-out and presence, offline delivery and multi-device sync, unread counts, membership changes, failure modes and observability. This walkthrough gives a corrected end-to-end reference answer for every part, including the trade-offs interviewers probe.
System DesignOnsite - AirbnbHardSoftware EngineerDesign a hot-listing waitlist API
Design a hot-listing waitlist API 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 DesignOnsite - AirbnbHardSoftware EngineerDesign a real-time chat system with hot groups
This problem tests your ability to design a distributed, low-latency messaging system that handles massive fan-out and identify trending group activities.
System DesignOnsiteDistributed SystemsWebSocketsCaching - AirbnbHardSoftware EngineerDesign a scalable consumer feature
This question evaluates a candidate's ability to design large-scale recommendation systems, covering system architecture, real-time serving and offline pipelines, personalization and ML modeling (candidate generation and ranking), data modeling/feature stores, caching and storage, monitoring, experimentation, and privacy/compliance skills.
System DesignOnsite - AirbnbHardSoftware EngineerDesign an A/B Testing Platform
Design an A/B testing platform with deterministic assignment, versioned experiment configuration, exposure logging, outcome attribution, and trustworthy analysis. Separate the latency-sensitive serving path from asynchronous metrics, support gradual ramps and overlapping tests, and detect bias, event loss, skew, and sample-ratio mismatch.
System DesignOnsite - AirbnbHardSoftware EngineerDesign multi-currency pricing end-to-end
This question evaluates understanding of multi-currency pricing and payments, covering currency selection UX, storage versus presentation currency, exchange-rate sourcing and locking, rounding and localization, tax and fee modeling, caching and cross-channel consistency, and API and data-model design in a distributed marketplace.
System DesignOnsite - AirbnbMediumSoftware EngineerDesign mutable sum-tree with fast queries
This question evaluates proficiency in designing dynamic data structures for mutable rooted trees, including maintenance of subtree sums, parent/child link management, and analysis of update and query complexities within the Coding & Algorithms domain; it emphasizes practical application of algorithmic design coupled with conceptual understanding of invariants and amortized complexity. It is commonly asked in technical interviews because it probes reasoning about correctness and performance under mutations, handling edge cases such as subtree deletion and reattachment, and the ability to specify algorithmic approaches and complexity guarantees rather than implementation details.
Coding & AlgorithmsOnsite - AirbnbHardSoftware EngineerDesign rental watchlist and notification system
This question evaluates system architecture and scalability competencies, including data modeling for date-range watchlists, event-driven notification pipelines, time-zone and DST handling, consistency and concurrency semantics, idempotency, sharding/caching strategies, and privacy/analytics considerations.
System DesignOnsite - AirbnbHardSoftware EngineerDesign scalable notification system
Airbnb's onsite system design round asks you to design a notification system that delivers email, SMS, and push messages to millions of guests, hosts, and employees, supporting both event-triggered sends and large batch campaigns. A complete answer covers requirements and scale math, architecture and data flow for both modes, the data model and API, templating, user preferences and compliance, prioritization, deduplication and idempotency, retries and failover, scaling and backpressure, observability, and cost. This walkthrough gives a corrected end-to-end reference answer for every part, including the trade-offs interviewers probe.
System DesignOnsite - AirbnbHardSoftware EngineerDetect overlap of two linked lists with cycles
This problem tests your ability to detect if two linked lists merge, specifically when they may contain cycles, by requiring logic to identify loop entry points and intersection nodes.
Coding & AlgorithmsOnsiteLinked ListTwo PointersCycle Detection - AirbnbMediumSoftware EngineerFind palindrome-forming string pairs
This question evaluates string-processing and algorithmic design skills, including knowledge of efficient lookup data structures, palindrome properties, handling of edge cases, and time/space complexity analysis.
Coding & AlgorithmsOnsite - AirbnbMediumSoftware EngineerFind smallest permutation under constraints
This problem tests your ability to manipulate digits and understand greedy strategies to construct the smallest possible number after applying specific constraints.
Coding & AlgorithmsOnsiteGreedyRecursionStrings - AirbnbHardSoftware EngineerFlatten a Nested Integer List
Flatten an arbitrarily deep mixture of integers and lists while preserving left-to-right order. The challenge emphasizes an iterative stack solution that handles empty lists, very deep nesting, and up to 200,000 nodes without mutating the input.
Coding & AlgorithmsOnsite - AirbnbHardSoftware EngineerHow do you conduct a code review exercise?
This question tests a software engineer's ability to conduct structured, high-signal code reviews under time pressure and limited context. It evaluates judgment in prioritizing correctness issues over style, communicating feedback clearly, and handling ambiguity — core competencies in software engineering fundamentals interviews.
Software Engineering FundamentalsOnsite - AirbnbMediumSoftware EngineerImplement a reservation widget with pricing
This question evaluates skills in frontend component state design, data modeling, pricing computation, validation logic, error handling, and API integration for a lodging reservation widget.
Software Engineering FundamentalsOnsite - AirbnbHardSoftware EngineerImplement retry wrapper and interdependent validators
This question evaluates a candidate's competence in building robust asynchronous utilities and form validation logic, covering retry/backoff strategies, error classification, per-attempt and overall timeouts, cancellation via AbortSignal, observable retry hooks, cross-field validators, state management, and accessibility considerations in JavaScript/TypeScript web applications. Category: Other / Miscellaneous; domain: web development and systems reliability in JavaScript/TypeScript; it is commonly asked because it probes both conceptual understanding of retry semantics, cancellation and validation constraints and practical implementation skills related to API ergonomics, error propagation, composable validators, and performance trade-offs.
Software Engineering FundamentalsOnsite - AirbnbMediumSoftware EngineerMaximize profit from non-overlapping jobs
This question evaluates proficiency in weighted interval scheduling, dynamic programming concepts, and the use of efficient data structures for large-scale scheduling problems, including handling duplicate times, large reward values, and memory constraints.
Coding & AlgorithmsOnsite - AirbnbHardSoftware EngineerMaximize sum with no adjacent tree nodes
This problem tests your ability to use tree-based dynamic programming to solve an optimization challenge where you must select a subset of nodes with no two being adjacent, while maximizing the sum of their values.
Coding & AlgorithmsOnsiteTree DPRecursionDFS - AirbnbMediumSoftware EngineerPrioritize consumer product opportunities
This question evaluates a candidate's ability in product strategy, data-driven user research, metric design, and prioritization within the product/decision-making domain for a consumer mobile application.
Behavioral & LeadershipOnsite - AirbnbMediumSoftware EngineerRender Wrapped Paragraphs Inside One Text Box
Implement a text formatting utility that wraps multiple paragraphs at distinct per-paragraph widths and renders them inside a single, uniformly padded ASCII border box.
Coding & AlgorithmsOnsiteStringGreedyImplementation - AirbnbMediumSoftware EngineerReview Python geodata code
This question evaluates proficiency in Python code review and geolocation data-processing, including competencies in readability, correctness, performance optimization, and architectural scalability.
Coding & AlgorithmsOnsite
Airbnb