Design Google Calendar
Medium · System Design · about 45 minutes
Asked at Google, Microsoft, Atlassian, Apple, Salesforce, Zoom, SAP, Glean.
Design a calendar service like Google Calendar for ~100M daily users. Users create one-off and recurring events, invite attendees who RSVP, view a day, week or month quickly, find a free time across a group, and get reminders before events — all correct across time zones and daylight-saving changes.