001 · Flight Booking / OTA

Trabill

OTA Platform

Production

2023

System

001

Year

2023

Duration

14 months

Team Size

6 engineers

Role

System Architect & Backend Lead

Full-scale Online Travel Agency system with GDS integrations

Overview

Trabill is an enterprise-grade OTA platform built to handle the full lifecycle of flight bookings — from real-time availability search through GDS aggregators to final ticketing and post-booking management. The system processes hundreds of thousands of API calls daily while maintaining sub-200ms response times through aggressive caching, connection pooling, and async processing via Server-Sent Events.

Key Achievements

Real-time flight search across Galileo and Sabre GDS with unified response schema

SSE-based fare streaming eliminates polling and cuts frontend load by 60%

Multi-agency tenant system with isolated financial ledgers per branch

Automated revalidation before payment to eliminate fare mismatch errors

Technical Challenges

GDS response normalization

Galileo and Sabre return wildly different XML/JSON schemas for the same flight data.

Solution →Built a normalisation adapter layer that maps both GDS responses into a single internal DTO before any business logic runs.

Real-time fare streaming

Polling-based fare updates created high backend load and stale UX.

Solution →Replaced polling with Server-Sent Events. The backend streams incremental fare updates as GDS responses arrive.

Concurrent booking race conditions

Simultaneous bookings for the same seat caused double-confirmation issues during peak traffic.

Solution →Implemented Postgres advisory locks combined with an idempotency key system so duplicate requests are safely collapsed.

metrics.json

500K+

API Calls / Day

<200ms

Response Time

99.8%

Booking Accuracy

99.95%

Uptime SLA

Technology

Backend

Node.jsTypeScriptExpressPrisma ORM

Database

PostgreSQLRedis (caching)Connection Pooling

Frontend

Next.js 14Redux RTK QueryTypeScript

GDS APIs

Galileo / TravelportSabre GDSSSE Streaming

Infra

DockerNginxAWS EC2PM2

Resources

Live Site

Development Timeline

Phase 01 · Discovery & Architecture

Requirements analysisGDS API evaluationSystem designDB schema

Fitsair Api Integration

Naria Erp