// TOPIC
#notifications
2 articles
◆◆IntermediateGoogleMicrosoft
01Design a Calendar System (Google Calendar)
Store events, share calendars, find free slots, and fire reminders — across time zones and recurring rules. The RRULE expansion and free/busy problem.
#interview#scheduling#consistency
23 min◆◆IntermediateMetaGoogle
02Design a Notification System (Push, Email, SMS)
A reliable multi-channel notification platform — fanout, templates, dedup, rate limiting, and the realities of APNS/FCM.
#interview#notifications#messaging
14 min