Ticketmaster System Design (Mock Interview + Inventory & Checkout)

Design a ticket booking platform like Ticketmaster that allows users to search for events, view available seats, and purchase tickets. The system must handle high concurrency during popular event sales and prevent overselling.

Constraints

Functional

Create/manage events with venues and seating, search by location/date/category, view seats and pricing, reserve and purchase, hold with expiry during checkout, payment, ticket delivery (email/app), waitlist for sold-out

Non-functional

Thousands of simultaneous bookings, no overselling, < 2s booking, strong consistency for inventory, 99.9% uptime, fair allocation (no bots/scalping)

Scale

100K events, 10K venues, 50M users, 5M DAU; 1M bookings/day, peak 10K/s; ~500M seats total; ~2 GB/day bookings

Stages ahead

1Requirement Analysis

2API Design

3High-Level Design

4HLD Extensions

5Trade-offs