From Custom Code to Cutting-Edge: On The Beach Adopts WunderGraph Cosmo for GraphQL Federation
How On The Beach Handles 4B+ Monthly Clicks with WunderGraph Cosmo
Company Overview
On the Beach is a UK-based online travel retailer that specializes in affordable beach holidays, packaging together flights and accommodation for millions of customers each year across European and long-haul destinations. Operating as a digital-first business, it uses a scalable, cloud-based technology platform to dynamically combine inventory, manage customer bookings end to end, and optimize performance, which has enabled rapid growth since its launch in 2004 and public listing on the London Stock Exchange in 2015.
The Challenge
A Growing Monolith That Couldn’t Scale Safely
On The Beach began modernizing its platform with microservices and a universal GraphQL API. As more domains were added, including Flights, Hotels, and Transfers, it began to behave like a monolith. Changes required coordination across teams, bottlenecks formed around a central schema, and performance issues became harder to diagnose. With rising post-pandemic traffic, reliability became a primary concern.
The team introduced GraphQL Federation to relieve the pressure, but the tooling created new challenges.
“We started building our own Federation Solution. We ended up implementing a home baked solution utilizing Apollo Rover and schema stitching. It worked for a while, but as we grew, it became more and more difficult to maintain, and harder for teams to adopt. We decided to look for a better solution.”
Their homegrown approach worked for a time, but as the graph continued to grow, it was clear they needed a more stable foundation. On The Beach had outgrown custom federation and required a platform built for reliability, safety, and long-term scale.
The Solution
A Safer, More Observable Federation with WunderGraph Cosmo
On The Beach chose to adopt Cosmo for its open-source transparency and the strong partnership behind it.
Why On The Beach Chose Cosmo
- Open source transparency
The team could inspect the code, understand how federation worked, and trust the behavior of the system.
- Schema Registry and Studio
A centralized workflow for safe schema changes, versioning, validation, and clear domain ownership.
- Advanced Request Tracing
Deeper insight into query behavior made it easier to diagnose issues and improve performance.
- Event Driven Federated Subscriptions
Real-time booking confirmations and pricing updates that scale without adding operational overhead.
- Self-hosted router
Increased control over performance tuning, networking, and cost, aligned with their infrastructure needs.
- Incremental migration
Subgraphs were moved one at a time, allowing the team to modernize safely with support from WunderGraph engineers.
The Results
A More Reliable, Faster, and Safer GraphQL Platform
By moving to WunderGraph Cosmo, On The Beach strengthened its GraphQL foundation and created a system that is scalable and easier to maintain.
Key outcomes
- A platform built for reliability
Cosmo replaced the stitching-based setup with automated composition, schema validation, and clear observability, giving the team more confidence in how changes move through the graph.
- Independent teams and faster releases
Domain teams now manage their own subgraphs, reducing coordination overhead and helping features move from idea to production more quickly.
- Better performance where it matters
Self-hosted router tuning and optimized query execution reduced latency during high-traffic periods and improved the overall booking experience.
- Stronger real-time experiences
Event Driven Federated Subscriptions made time-sensitive flows more dependable, including booking confirmations and dynamic pricing.
- Deep visibility and safer debugging
Advanced Request Tracing gives engineers a clear view of how queries execute, making it easier to diagnose issues and improve performance.
- An architecture aligned with how teams work
Product requirements now map more naturally to domain-driven schemas, and Cosmo helps keep schema changes safe, predictable, and collaborative.
The Conclusion
From Custom Code to a Future-Ready Federation Platform
On The Beach modernized its GraphQL architecture with a platform that provides clearer visibility, safer change management, and room to grow. Cosmo supported the way their teams already worked and helped reduce the operational overhead of maintaining a custom federation approach.
By adopting WunderGraph Cosmo, On The Beach:
- More predictable schema changes and collaboration across teams
- Improved performance and reliability during high-traffic periods
- Clearer insight into query behavior for faster debugging and refinement
Ready to scale without the chaos?
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