Design a Slack-like chat systemSystem designWorkspaces, channels, threads and direct messages with real-time delivery, unread state, search and history, for large companies.
Last asked Jun 2026
Airbnb system design interview
Round 7 of 9 · 23 questions reported
- Length
- 60 min
- Format
- Design discussion
- They grade
- A complete schema and scaling story; at senior levels, at least one deep dive
- Heads-up
- Two rounds at senior and staff, the second deliberately open. MLE candidates get ML design rounds instead of one or both.
Questions Airbnb asks in this round 23
- Design a distributed key-value storeSystem designStore and serve billions of keys with low latency, partitioned across machines and replicated to survive failures, with tunable consistency.Last asked May 2026
- Design a reliable job schedulerSystem designDesign a service that runs jobs at scheduled times at large scale, such as payment jobs that must run on time and exactly once in effect. Cover storing schedules, finding jobs…Last asked Aug 2026
- Design a hotel booking systemSystem designSearch hotels by place and dates, show availability and prices, and book rooms without double-booking, including holds and cancellations.Last asked Jun 2026
- Design Airbnb's notification systemSystem designSend booking confirmations, reminders and host messages over push, email and SMS, respecting user preferences and time zones, without duplicates.Last asked Dec 2025
- Design a personalized search ranking systemML designRank search results for each user's query and context so they find and book (or order) what they want, learning from clicks and conversions.Last asked Sep 2026
- Model cumulative booking metrics and first and last booking timesSystem designA data engineering round: design the tables and pipeline that report cumulative booking metrics over time, along with each user's (or listing's) first and last booking time. Cover…Last asked Sep 2026
- Turn company policies into step-by-step support instructionsAI systemDesign a retrieval-augmented system for customer support staff: given a user's issue, it reads the company's policies and produces step-by-step instructions the agent can follow…Last asked Sep 2026
- Design a customer support ticketing systemSystem designCustomers open tickets by email, chat or web; agents get them routed by skill and priority, with SLAs, escalation and full history.Last asked Jun 2026
- Design a family-friendly listing ranking systemML designFor guests traveling with children, rank listings by how family-friendly they are, without reliable labels for 'family-friendly'.Last asked Apr 2026
- Semantic search with user embeddingsML designDesign search that uses embeddings of users together with embeddings of listings, so results match both the request and the person searching. Cover how the user and item…Last asked Apr 2026
- Design an A/B testing platformSystem designDesign a platform that lets teams run A/B tests: define an experiment, assign users to variants consistently, log exposures and events, and compute results with confidence…Last asked Apr 2026
- Design photo and listing quality modelsML designDesign models that score the quality of listing photos and of listings overall, so better listings can be surfaced and hosts can be told what to improve. Cover defining quality…Last asked Jan 2026
- Design a user activity query systemSystem designDesign a system that stores user activity events at scale and lets services query a user's activity, for example everything a user did in a time range, filtered by type. Cover the…Last asked Dec 2025
- Design a listing watchlist with availability alertsSystem designUsers can add rental listings to a watchlist and get notified when something they care about changes, such as dates opening up or a price drop. Design it: the watchlist data…Possibly retired
- Design a customer lifetime value prediction systemML designDesign a machine learning system that estimates each user's long-term value on the platform. Cover defining the target and horizon, labels when long-term value is not yet known…Possibly retired
- Design a listing price suggestion systemML designSuggest a nightly price for each listing and date that hosts will accept and that books, adapting to seasonality, events and local demand.Possibly retired
- Design a waitlist for in-demand listingsSystem designWhen a popular listing is not available for the dates a guest wants, the guest can join a waitlist. Design the API and system behind it: joining and leaving, detecting when the…Possibly retired
- Design a distributed job schedulerSystem designDesign a service that runs millions of scheduled and on-demand jobs (cron-like and one-off) reliably across a fleet of workers.
- Design a duplicate listing detection systemML designFind hosts who relist the same property under a new listing (to shed bad reviews or evade bans), using text, photos, location and host signals.
- Design an ad click aggregation systemSystem designCount ad clicks per ad and per time window from billions of events a day, accurately enough to bill advertisers, with results available within minutes.
- Design an online chess gameSystem designMatch players of similar rating, play live games with clocks, handle disconnects and reconnects, and keep game history and ratings.
- Design Google CalendarSystem designCreate events, invite people, handle recurring events and time zones, show free/busy, and send reminders, for hundreds of millions of users.