Global Class Offering Booking System

Backend service for managing course offerings, sessions, and bookings for a live-learning platform.

Tech Stack

• Java 21
• Spring Boot 3
• Spring Data JPA
• MySQL
• Docker

Features

• Create offerings
• Add sessions to offerings
• View offerings and sessions in the parent's local timezone
• Book offerings
• View booked offerings
• Prevent overlapping bookings
• Idempotent booking requests
• Concurrency handling using optimistic and pessimistic locking

Running the Application

Build the application:

mvn clean package

Run using Docker:

docker-compose up --build

Application URL:

http://localhost:8080/api

API Testing

Postman collection is available under:

postman/Global-Booking-System.postman_collection.json

Import the collection into Postman and execute the available requests.

Key Design Decisions

• Session timings are stored in UTC.
• Teachers create sessions using their local timezone.
• Parents view sessions in their own timezone.
• Booking happens at the offering level.
• Pessimistic locking is used during booking to prevent conflicting concurrent requests.
• Optimistic locking is implemented using @Version.
• Idempotency keys prevent duplicate booking creation during retries.

Assumptions

• Authentication and authorization are out of scope.
• Offerings do not have capacity limits.
• Parents book an entire offering rather than individual sessions.
• Session overlap is checked across all sessions belonging to booked offerings.

Project Structure

src/main/java/com/assignment/booking

├── controller
├── service
├── serviceimpl
├── repository
├── entity
├── dto
├── mapper
├── exception
├── util
└── config