+4Design a notification systemSystem designA shared service other teams call to send push, email and SMS notifications: templates, user preferences, retries, deduplication and rate limits.
Last asked Sep 2026
#notifications
- +4
Design a matchmaking service for an online gameSystem designDesign a matchmaking service. It must let players join the queue and cancel, match two compatible players, notify both when a match is found, and deal with disconnects and…Last asked Sep 2026
Design an OS notification platform, working with an AI assistantSystem designDesign the notification system of a desktop operating system: the platform piece that lets many applications raise notifications and shows them to the user. Cover the app-facing…Last asked Sep 2026
Design a personalized weekly deals serviceSystem designEvery week each user gets a set of deals picked for them. Design how deals are collected, matched to each user, stored and delivered, and how the weekly run stays on time as users…Last asked Jul 2026
+3Design Google CalendarSystem designCreate events, invite people, handle recurring events and time zones, show free/busy, and send reminders, for hundreds of millions of users.Last asked Jun 2026- Design re-engagement notifications for inactive usersSystem designDesign a system that brings back users who stopped using an AI assistant product: decide who to contact, when and over which channel, what to say, how often, and how to measure…Last asked Apr 2026
Design a price tracking serviceSystem designTrack the prices of millions of products across stores and alert users when a product they watch drops below their target price.Last asked Mar 2026- Design a notification ranking systemML designMany products send notifications to the same user: new products, friends' activity, results of advertisers' campaigns and more. Design the ML system that decides which…Last asked Jan 2026
Design stock price alertsSystem designUsers set alerts such as "tell me when this stock goes above a price". Design the system that watches live prices and notifies the right users quickly. Cover how alert rules are…Last asked Dec 2025
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 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…Last asked Sep 2025
- 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…Last asked Jul 2025
Make sure every cluster job completesSystem designA company runs many jobs on a high-performance cluster and needs a service that makes sure every one of them completes. You get two functions (for example, one that starts a job…Last asked Jul 2025