Airline Booking System
A comprehensive microservices-based airline booking platform with robust data management and transactional integrity.
ExpressJs, NodeJs, MySQL, Sequelize ORM | Jul 2025 – Aug 2025
| Service | Architecture | Scale |
|---|---|---|
| Microservices | 2 Dedicated Services | Flight Data & Bookings |
Overview
A scalable airline booking system built with microservices architecture, featuring comprehensive flight data management, real-time seat availability, and secure booking transactions with automated cleanup processes.
Key Highlights
- Microservices Architecture: Strategic separation of booking logic from flight data management.
- ACID Transactions: Rollback mechanisms for secure booking operations.
- High-Performance APIs: Dynamic filtering and real-time airplane lookup.
- Relational Database: Foreign key constraints ensuring data integrity.
- Automated Cleanup: Cron jobs for unconfirmed booking management.
- Idempotent APIs: Prevention of duplicate booking submissions via
x-idempotency-key.
Interactive System Flow
System Architecture
The system consists of two dedicated microservices: 1. Flight Data Service: Manages cities, airports, flights, and airplanes. 2. Booking Service: Handles transactional booking logic, payments, and seat allocation.
Booking Lifecycle Flow
stateDiagram-v2
[*] --> INITIATED: User starts booking
INITIATED --> BOOKED: Booking created successfully
BOOKED --> PAID: Payment processed with Idempotency Key
BOOKED --> FAILED: Payment failed
PAID --> [*]: Booking complete
FAILED --> [*]: Booking cancelled (Seats Released)Features
Data Management
- Comprehensive Models: Cities, airports, flights, and airplanes with data validation.
- Relational Integrity: Strict MySQL foreign key constraints across all entities.
- Optimized Queries: Join operations for efficient JSON responses.
Flight Operations
- Dynamic Search: Filter flights by departure/arrival airports.
- Real-time Availability: Live airplane lookup functionality.
- Seat Management: Automated seat allocation and real-time availability tracking.
Booking & Payment System
- ACID Compliance: Transaction rollback mechanisms across multi-step bookings.
- Idempotency Keys: Guarantee exactly-once processing to prevent duplicate payments and double bookings.
- Race Condition Prevention: Secure concurrent booking handling using pessimistic locking.
- Automated Cleanup: Background cron jobs release unconfirmed reservations after 15 minutes, optimizing seat availability.
Tech Stack
Backend Core
Runtime │ Node.js 18+ with Express.js
Architecture │ Microservices with REST APIs
Background Jobs │ Automated Cron scheduling