Travel & Hospitality
Travel & Hospitality
Comprehensive guide to travel technology including airline reservation systems, hotel management, OTAs, GDS, and travel distribution networks.
$9.5T
Global Market
65%+
Online Bookings
$125B
India Market
17M+
Hotel Rooms
What Engineers Miss When They First Enter Travel & Hospitality
Travel technology is built around inventory management under time pressure and with perishable stock. A flight seat that departs empty is revenue lost forever — unlike unsold inventory in a warehouse that can be sold tomorrow. This fundamental economics drives the revenue management discipline: airlines and hotels use sophisticated pricing models to maximise the yield from every departure and every room night, adjusting prices in real time based on current booking pace, competitor pricing, and historical demand patterns for similar dates and events. The engineer who builds these systems is implementing applied operations research, not just a pricing table.
The Global Distribution System (GDS) — Amadeus, Sabre, Travelport — is the travel industry's shared inventory and reservation infrastructure, and understanding it is essential for engineers working in travel. Airlines publish their fares and availability to the GDS, travel agents and OTAs query the GDS to search and book flights, and the GDS maintains the booking record (PNR — Passenger Name Record) that is the canonical source of truth for the reservation. The GDS is 50-year-old technology that has been incrementally modernised, and its data models reflect that history: fare structures in Sabre's booking protocol are vastly more complex than anything a modern engineer would design from scratch, but they reflect the full complexity of airline fare rules accumulated over decades.
India's IATA NDC (New Distribution Capability) adoption has been uneven, which creates interesting technical challenges for OTAs. NDC is an API standard that allows airlines to sell directly to travel agents and OTAs without going through the GDS, enabling airlines to offer ancillary services (extra baggage, seat selection, meals) and personalised offers that the GDS's legacy architecture does not support. IndiGo and Air India have been pushing NDC-direct connections with OTAs, which requires OTAs to implement separate API integrations for each airline rather than querying a single GDS. Managing these multiple airline direct connections alongside GDS connections, with their different fare structures and booking flows, is a significant integration complexity.
What Teams Actually Do Day To Day
- 1Build the flight search aggregation and caching layer: querying multiple GDS (Amadeus, Sabre), airline NDC APIs, and LCC (Low Cost Carrier) direct APIs simultaneously for a search query, combining and deduplicating results into a consistent fare object model, applying fare rules to compute refundability and change fees, and caching results to avoid re-querying for the same route and date within a short window.
- 2Develop the booking and ticketing flow: creating a PNR in the GDS or airline NDC, collecting passenger details (name matching passport exactly for international travel), processing payment via payment gateway, issuing the e-ticket, and sending the booking confirmation with the e-ticket number. Handling booking failures — seat sold out between search and booking, card payment failed — with appropriate user feedback.
- 3Implement revenue management for hotel and tour products: defining rate plans with season-specific pricing, blackout dates, and minimum stay requirements; managing overbooking thresholds for rooms likely to have cancellations; setting up last-minute discount rules for unsold inventory; and generating yield reports showing RevPAR by date.
- 4Build post-booking servicing workflows: flight change handling (informing customers of airline-initiated flight changes, offering alternatives, processing refunds for eligible cancellations), hotel booking modifications, ancillary service addition (seat upgrades, extra baggage), and the refund calculation and processing that applies each airline's complex fare rules to determine refund eligibility and amount.
- 5Develop the travel operations and support tools: the agent-facing booking management interface, the disruption management tools that help agents rebook customers affected by cancellations or delays, the reporting dashboards that track booking volumes and conversion rates, and the customer communication automation for itinerary reminders and check-in prompts.
One End-to-End Flow: An OTA Searches and Books a Round-Trip Flight
A customer searches for a Mumbai-Delhi round trip on MakeMyTrip. The OTA queries multiple sources simultaneously, shows results, the customer books, and the e-ticket is issued — with the PNR as the thread connecting all systems.
Customer submits search and OTA queries sources
The customer enters Mumbai-Delhi, round trip, specific dates. MakeMyTrip's search service fires simultaneous queries to Amadeus GDS for all airlines, IndiGo's NDC direct API, and SpiceJet's direct API. Responses arrive within 2-3 seconds. The results are merged and sorted by price.
Systems Involved
OTA search API, Amadeus GDS SOAP/REST, airline NDC API, result aggregation and deduplication
Where It Usually Breaks
GDS query timeouts (the GDS takes longer than 3 seconds for a complex multi-city search) cause partial results to be displayed without the missing airline's fares. Customers who compare and select based on partial results may see a different (higher) price when they book if the cheaper option from the slow source returns after the comparison page loads.
Customer selects a fare and seat inventory is held
The customer selects an IndiGo round trip. The OTA sends an availability check to IndiGo's NDC to confirm the fare and seat count is still available. If confirmed, a temporary seat hold is created (valid 15 minutes). The customer proceeds to enter passenger details.
Systems Involved
Airline availability check, seat hold via NDC/GDS, countdown timer
Where It Usually Breaks
The 15-minute hold window is often too short for customers who pause to compare passport details or discuss with family. When the hold expires, the customer loses the selected seats and may find the fare has increased (adjacent availability class sold out).
Payment is captured and PNR is created
The customer completes payment. On success, MakeMyTrip calls IndiGo NDC to confirm the booking and create the PNR. IndiGo returns a PNR reference. The OTA stores the PNR with the booking record. The airline issues an e-ticket number linked to the PNR.
Systems Involved
Payment gateway, airline booking API (NDC), PNR creation, e-ticket issuance
Where It Usually Breaks
Payment captured but booking confirmation failed — the airline's system was slow and the OTA's booking confirmation timed out after payment was charged. The customer is charged but has no confirmed ticket. The OTA support team must manually verify with the airline and either confirm the booking or issue a refund.
E-ticket is sent and itinerary is stored
MakeMyTrip sends the booking confirmation email with the e-ticket PDF and the PNR reference for web check-in. The itinerary is added to the customer's app under 'My Trips'. The airline's check-in reminder is scheduled for 48 hours before departure.
Systems Involved
E-ticket PDF generation, email dispatch, trip storage, scheduled notification
Where It Usually Breaks
E-ticket emails delivered to spam, or confirmation not received if the email address was entered incorrectly during booking, leave the customer uncertain about whether the booking is confirmed. Customers who cannot find confirmation frequently call support to verify.
Technology Architecture — How Travel & Hospitality Platforms Are Built
The diagram below reflects how production Travel & Hospitality systems are structured at scale — nine layers from client channels through edge security, API gateway, domain microservices, polyglot data stores, async event streaming, analytics, external partners, and cloud infrastructure. Solid arrows show synchronous REST/gRPC calls; dashed arrows show async event flows via Kafka or a message queue.
Industry Players & Real Applications
🇮🇳 Indian Companies
MakeMyTrip
OTA
Custom, AWS
India's largest OTA, includes Goibibo
ixigo
Meta-search/OTA
AI-powered, Cloud
Train + flight focus, IPO 2024
Yatra
OTA
Custom Platform
Strong corporate travel business
Cleartrip
OTA
Custom, Flipkart-owned
Part of Flipkart ecosystem
EaseMyTrip
OTA
Custom Platform
Zero convenience fee model
IRCTC
Railways Booking
Custom, NIC
1M+ tickets/day, world's largest
OYO Rooms
Hotel Chain/Tech
OYO OS, Custom
Technology-driven budget hotel chain
Taj Hotels (IHCL)
Luxury Hotels
Opera PMS, Custom
India's iconic luxury hotel brand
🌍 Global Companies
Booking Holdings
USAOTA Giant
Custom, Multi-brand
Booking.com, Priceline, Kayak, Agoda
Expedia Group
USAOTA Giant
Custom Platform
Expedia, Hotels.com, Vrbo
Amadeus
SpainGDS + Tech
Amadeus Altea, Custom
Largest GDS, airline IT provider
Sabre
USAGDS + Tech
SabreSonic, Custom
GDS, airline and hotel solutions
Travelport
UKGDS
Galileo, Apollo, Worldspan
Third major GDS
Marriott International
USAHotel Chain
Custom, Oracle
World's largest hotel company
Airbnb
USAAlternative Lodging
Custom, AWS
Disrupted traditional hospitality
Trip.com
ChinaOTA
Custom Platform
Asia's largest OTA
🛠️ Enterprise Platform Vendors
Amadeus
Altea PSS, Hospitality, Cytric
Powers 150+ airlines
Sabre
SabreSonic PSS, SynXis, Hospitality
Airline and hotel tech leader
Oracle Hospitality
Opera PMS, Simphony POS, MICROS
Dominant hotel PMS vendor
IBS Software
iFly Res, iCargo, iHMS
Growing airline tech from India
Travelsky
TravelSky PSS
Chinese airline IT, world's largest by passengers
Mews
Mews PMS, Guest Journey
Cloud-native hotel PMS
Cloudbeds
PMS, Channel Manager, Revenue
All-in-one hotel management
RateGain
OPTIMA, DHISCO, DaaS
Distribution and revenue tech
Real World Use Cases
Airline Technology
PSS, revenue management, flight operations
Explore →Hotel Technology
PMS, channel management, guest experience
Explore →OTAs & Distribution
Online booking, GDS, aggregation
Explore →Corporate Travel
TMC, expense management, policy
Coming SoonCore Systems
These are the foundational systems that power Travel & Hospitality operations. Understanding these systems — what they do, how they integrate, and their APIs — is essential for anyone working in this domain.
Business Flows
Key Business Flows Every Developer Should Know.Business flows are where domain knowledge directly impacts code quality. Each flow represents a real business process that your code must correctly implement — including all the edge cases, failure modes, and regulatory requirements that aren't obvious from the happy path.
The detailed step-by-step breakdown of each flow — including the exact API calls, data entities, system handoffs, and failure handling — is covered below. Study these carefully. The difference between a developer who “knows the code” and one who “knows the domain” is exactly this: the domain-knowledgeable developer reads a flow and immediately spots the missing error handling, the missing audit log, the missing regulatory check.
Technology Stack
Real Industry Technology Stack — What Travel & Hospitality Teams Actually Use. Every technology choice in Travel & Hospitalityis driven by specific requirements — reliability, compliance, performance, or integration capabilities. Here's what you'll encounter on real projects and, more importantly, why these technologies were chosen.
The pattern across Travel & Hospitality is consistent: battle-tested backend frameworks for business logic, relational databases for transactional correctness, message brokers for event-driven workflows, and cloud platforms for infrastructure. Modern Travel & Hospitalityplatforms increasingly adopt containerisation (Docker, Kubernetes), CI/CD pipelines, and observability tools — the same DevOps practices you'd find at any modern tech company, just with stricter compliance requirements.
⚙️ backend
Java/Spring Boot
Core booking systems, PSS, PMS
Node.js
API aggregation, real-time services
Python
ML for pricing, recommendations
Golang
High-performance search, caching
🖥️ frontend
React/Next.js
OTA websites, booking engines
React Native/Flutter
Travel mobile apps
Vue.js
Admin portals, dashboards
🗄️ database
PostgreSQL
Booking data, inventory
MongoDB
Hotel content, reviews
Elasticsearch
Search, autocomplete
Redis
Session cache, availability cache
Apache Kafka
Event streaming, booking events
🔗 integration
NDC APIs
Modern airline distribution
SOAP/XML
Legacy GDS integration
REST APIs
Modern supplier integration
GraphQL
Flexible frontend data fetching
☁️ cloud
AWS/GCP
Cloud infrastructure
CDN
Static content, images
Kubernetes
Container orchestration
Interview Questions
Q1.What is a GDS and how does it work?
GDS (Global Distribution System) is a computerized network connecting travel suppliers (airlines, hotels, car rentals) with travel agents and OTAs. Major GDSs: Amadeus, Sabre, Travelport. Airlines file their fares and inventory to GDS. Travel agents query GDS to search, book, and issue tickets. GDS charges booking fees to airlines and subscription fees to agents. Revenue model is under pressure from NDC which enables direct airline-to-OTA connections.
Q2.Explain IATA NDC and why airlines are adopting it.
NDC (New Distribution Capability) is IATA's XML/JSON-based standard for airline retailing. Unlike GDS which shows basic fares, NDC enables rich content (images, ancillaries, branded fares), dynamic pricing, and personalization. Airlines adopt NDC to: bypass GDS fees, control their retail experience, sell ancillaries better, and offer personalized prices. OTAs integrate NDC to get better content. Challenge: Each airline has slightly different NDC implementation.
Q3.How does hotel inventory distribution work?
Hotels distribute inventory through multiple channels: direct (hotel website), OTAs (Booking.com, MakeMyTrip), GDS (for corporate/TMC), wholesalers/bed banks, and meta-search. Channel Manager connects PMS to all channels, maintains rate parity, and syncs availability in real-time. When booking comes from any channel, availability updates everywhere. Challenge: managing rate parity, channel mix optimization, and commission costs (OTA fees 15-25%).
Q4.What is revenue management in travel?
Revenue management optimizes pricing to maximize revenue given perishable inventory (airline seats, hotel rooms). Core concepts: demand forecasting, dynamic pricing based on demand/competition, fare class inventory control. Airlines use booking curves, historical data, and ML to forecast. Hotels track pickup pace, competitor rates, and events. System recommends prices, but revenue manager often has override. Key metrics: RevPAR (hotels), RASM (airlines), load factor.
Q5.How do you handle flight search at scale?
Flight search is compute-intensive: query multiple suppliers (GDS, NDC, direct), handle millions of fare combinations, respond in <3 seconds. Architecture: Cache static data (schedules, fare rules), use distributed search (parallel supplier queries), implement result caching (Redis), pre-compute popular routes, use smart truncation for long-haul multi-city. Aggregation layer dedupes and ranks results. Consider latency vs completeness trade-off.
Q6.What happens when a flight is cancelled?
When airline cancels flight: 1) PSS marks flight cancelled, inventory released. 2) Affected PNRs identified, passengers notified. 3) Rebooking options generated (next available flights). 4) Passengers can rebook online or via call center. 5) If no rebooking, full refund processed. 6) If OTA booking, OTA system syncs with airline for status. Challenges: downstream hotel/car cancellations, communicating with passengers, handling surge in call center. Airlines increasingly automate rebooking.
Glossary & Key Terms
PSS
Passenger Service System - airline reservation and departure control
PMS
Property Management System - hotel operations software
GDS
Global Distribution System - Amadeus, Sabre, Travelport networks
OTA
Online Travel Agency - MakeMyTrip, Booking.com, Expedia
NDC
New Distribution Capability - IATA's modern airline retailing standard
PNR
Passenger Name Record - booking record with 6-character locator
RevPAR
Revenue Per Available Room - key hotel performance metric
ADR
Average Daily Rate - average room rate sold
OCC
Occupancy Rate - percentage of rooms sold
BAR
Best Available Rate - lowest unrestricted rate
DCS
Departure Control System - manages check-in and boarding
TMC
Travel Management Company - corporate travel agency