Requirements

Functional Requirements:

• Users can see available shows.
• Users can view a seating map to pick seats.
• Users can choose their desired seats, make an order and pay for tickets
• Users can choose different level of tickets and pricing will be different
• Users can cancel tickets according to the cancellation policy
• Users can modify bookings (changing seats, upgrading) according to the change policy
• The system sells exactly the amount of tickets for an event

Non-Functional Requirements:

• 10-20 million DAU
• Peak QPS to be between 100k to 1 million
• SLA 99.9%
• Backup systems and recover quickly from outages
• Should be able to scale horizontally
• Monitoring for: number of tickets sold per second, number of failed purchases, number of failed payment,
• Alarm: Spike in number of failed purchases or number of failed payment

API Design

Get /v1/events: show available events

GET /v1/events/{eventId}/seats: show seatmap for specific event

POST /v1/events/{eventId}/seats/reserve: reserve particular seats. Response contains a list of seats which will be reserved.

POST /v1/events/{eventId}/seats/unreserve: cancel reserve particular seats

GET /v1/events/{eventId}/seats/reserved: Check reserved seats for current user. Returns a list of

POST /v1/events/{eventId}/booking: Make a booking with a list of reserved seats. Returns the booking result and a booking id

POST /v1/events/{eventId}/booking/

High-Level Design

Describe the overall system architecture. Identify the main components needed to solve the problem end-to-end. Use the diagramming tool to create a block diagram.

Detailed Component Design

Deep dive into 2-3 key components. Explain how they work, how they scale, discuss tradeoffs, capacity, and any relevant algorithms or data structures.