# Field Notes on Travel Technology | OnArrival > Essays from the people building travel infrastructure: airline distribution, hotel mapping, loyalty economics, payments, SDK architecture and AI agents. Source: https://www.onarrival.com/blog --- # Travel, beyond *the booking.* OnArrival field notes Notes from the people building OnArrival: booking systems, hotel mapping, payments, refunds and the decisions behind them. VOL. 0119 ESSAYS BUILDING AND RUNNING TRAVEL · FIELD NOTES 01 EDITOR'S PICK [Technical architecture · 8 min Dynamic airline pricing: when the cached fare is wrong When an airline calculates an offer for each search, a cached fare may no longer explain the price. Booking systems need to retain the quote, its conditions and when it expires. **Pawan Shetty** *Co-Founder and CTO* Read the essay](https://www.onarrival.com/blog/a-price-used-to-be-data) THE LIBRARY ## Architecture, operations and commercial decisions. For teams shipping and operating travel products. 18 ESSAYS Every essay in the library. [Engineering · 12 min One travel SDK. Five platforms. The same booking rules. We moved shared booking rules into a Kotlin Multiplatform core for web, iOS, Android, Flutter and React Native. Each host runs the same checks so prices, dates and decisions agree. **Pawan Shetty** *Co-Founder and CTO*](https://www.onarrival.com/blog/one-core-five-hosts) [Strategy · 9 min Why travel infrastructure has to work after checkout The comparison with payment infrastructure is useful until a confirmed trip changes. Travel infrastructure also has to manage supplier updates, booking changes, refunds and settlement. **Ankit Sawant** *Co-Founder and CEO*](https://www.onarrival.com/blog/stripe-analogy-breaks-after-checkout) [AI and agents · 12 min AI travel agents need booking permissions and spending limits An AI agent can find a trip without having permission to buy it. Booking needs separate checks for the approved price, traveller, budget and any repeated request. **Pawan Shetty** *Co-Founder and CTO*](https://www.onarrival.com/blog/agentic-travel-mcp-guardrails) [Comparison · 11 min NDC, GDS and LCC direct: choosing the right mix The right mix depends on the routes, fares and servicing your customers need. Compare airline content sources without forcing each supplier workflow into your checkout. **Ankit Sawant** *Co-Founder and CEO*](https://www.onarrival.com/blog/ndc-gds-lcc-comparison) [Technical architecture · 11 min Travel API architecture needs orders, state and recovery Supplier adapters handle API calls. A travel platform also needs a shared booking record, permission checks and recovery when a supplier response is late or unclear. **Pawan Shetty** *Co-Founder and CTO*](https://www.onarrival.com/blog/travel-api-architecture-control-plane) [Product · 10 min Embedded travel for fintechs: connect booking to the rest of the app A travel feature is more useful when it works with the customer identity, payment method and rewards already in the app. That connection also needs to survive a change or refund. **Ankit Sawant** *Co-Founder and CEO*](https://www.onarrival.com/blog/embedded-travel-for-fintechs) [Business · 11 min Build vs. buy travel infrastructure: plan beyond launch A search-and-book estimate leaves out supplier maintenance, booking changes, refunds and support. The build-versus-buy decision needs to include who runs those operations after launch. **Ankit Sawant** *Co-Founder and CEO*](https://www.onarrival.com/blog/build-vs-buy-travel-infrastructure) [Technical · 9 min The NDC capability matrix: what to check before integrating An NDC label does not tell you which bookings a connection can service. Check shopping, booking, changes, refunds and disruption support for the markets you plan to sell. **Aditi Acharya** *Product*](https://www.onarrival.com/blog/ndc-capability-matrix) [Technical · 11 min What to monitor after a travel booking is confirmed Search latency cannot tell you whether a flight changed or a refund arrived. Post-booking monitoring needs to detect supplier changes, missing updates and delays in telling the traveller. **Manan Vaghasiya** *Principal Engineer*](https://www.onarrival.com/blog/observability-stops-at-checkout) [Business · 11 min Travel loyalty points: what redemption really costs The cost of issuing points is only part of loyalty economics. Travel redemption also depends on supplier prices, the value promised to members and what happens when a booking is cancelled. **Ankit Sawant** *Co-Founder and CEO*](https://www.onarrival.com/blog/points-are-a-liability-not-a-currency) [Data and supply · 11 min How we built our hotel and room mapping pipeline Our mapping pipeline compares supplier records, checks room attributes and sends uncertain matches for review. The key is keeping the evidence behind each decision. **Pranav Upadhyay** *Product*](https://www.onarrival.com/blog/how-we-solved-room-mapping) [Technical architecture · 11 min Why a travel cart needs more than one checkout call Flights, hotels and activities can expire or fail independently during checkout. A travel cart needs price checks, booking recovery and a payment plan for partial success. **Manan Vaghasiya** *Principal Engineer*](https://www.onarrival.com/blog/the-travel-cart-problem) [Technical · 11 min What NDC does not fix in your booking product NDC can improve the airline offers you sell. Your product still needs to handle different carrier capabilities, booking changes, refunds and incomplete responses. **Aditi Acharya** *Product*](https://www.onarrival.com/blog/why-ndc-wont-solve-your-immediate-problems) [Technical · 12 min Travel payments: keep bookings, refunds and settlement connected A successful payment does not mean every part of a trip is confirmed or settled. Track customer charges, supplier payments and refunds against the booking they belong to. **Manan Vaghasiya** *Principal Engineer*](https://www.onarrival.com/blog/unified-payments-refunds-reconciliation) [Data and supply · 11 min Hotel mapping: why one property appears five times Different suppliers can list the same hotel under different names. Hotel mapping joins those records while keeping room types, rate conditions and booking references distinct. **Pranav Upadhyay** *Product*](https://www.onarrival.com/blog/hotel-mapping-deduplication) [Operations · 10 min Post-booking service: who handles changes and refunds? A confirmed booking still needs support when a flight changes, a traveller cancels or a refund is delayed. Customers need a clear status, a next step and someone responsible for the outcome. **Ankit Sawant** *Co-Founder and CEO*](https://www.onarrival.com/blog/post-booking-is-the-trust-product) [Product engineering · 11 min The travel order lifecycle: from search to refund settlement A travel order records the offer, confirmation, booking changes and related payments. Keeping that history together makes partial cancellations and delayed refunds easier to handle. **Manan Vaghasiya** *Principal Engineer*](https://www.onarrival.com/blog/travel-order-lifecycle) [Strategy · 10 min When should you add travel to your app? Travel makes sense when it improves a job your customers already do in your app. Before launching, decide who owns booking changes, customer support and refunds. **Ankit Sawant** *Co-Founder and CEO*](https://www.onarrival.com/blog/when-to-add-travel-as-a-product) HAVE A REAL ITINERARY? ## Let’s map the systems behind it. [Talk to OnArrival](https://www.onarrival.com/demo)