For a lot of app-owning businesses, the problem isn’t that the app is failing. It’s that the structure behind it makes every improvement harder than it should be.
That’s particularly common in businesses that built their iOS and Android apps separately over time. Initially, it works. Teams move quickly, platforms evolve independently, and customer demand is manageable.
Eventually, though, duplication starts affecting delivery.
Every feature needs building twice. Every release requires additional coordination. Testing becomes more complicated. Small differences between platforms create inconsistencies in the customer experience, while development teams spend more time maintaining parity than improving the product itself.
We saw this with Big Bus Tours, the world’s largest open-top sightseeing bus company, operating across 28 cities and 18 countries. As mobile became a more important part of ticket sales, onboarding and customer engagement, the limitations of their existing setup became harder to ignore.
Their app itself wasn’t fundamentally broken. The issue was structural.
Big Bus Tours were maintaining two separate codebases. Their iOS app was built in Swift, while Android was built in Kotlin. Both delivered the same customer experience on the surface, but behaved differently underneath, creating inconsistencies in user journeys and increasing the operational burden internally.
Development effort was effectively doubled. Maintaining feature parity required constant coordination, while fragmented documentation and limited development continuity made the platform increasingly difficult to evolve over time.
Importantly, this wasn’t a crisis rebuild scenario.
The apps were functional, and the business had already invested heavily in the platform. What Big Bus Tours needed was a more sustainable technical foundation that would allow the product to evolve more efficiently as customer expectations around digital booking and ticketing continued to grow.
We started by stabilising the existing apps and introducing clearer testing and visibility processes through our Mobile Assurance Programme. That gave both teams a reliable understanding of how the apps were performing in real-world conditions and created a stronger operational baseline to work from.
From there, we recommended consolidating the platform into a cross-platform React Native app.
The goal wasn’t to redesign the experience or introduce unnecessary complexity. It was to simplify delivery. One codebase instead of two. One implementation of each feature. One consistent customer experience across both platforms.
Because we had already spent significant time working closely with the existing apps, we were able to approach the rebuild pragmatically. We rebuilt the product like-for-like, using our understanding of the existing systems, edge cases and customer journeys to shape the implementation.
That mattered for two reasons.
First, it reduced delivery risk. The rebuild wasn’t based on assumptions or speculative redesign decisions. Second, it allowed Big Bus Tours to modernise the platform without disrupting the customer experience that already worked well.
The rebuild ultimately became the largest digital initiative Big Bus Tours had undertaken at that point, delivered on time and on budget.
The immediate impact was operational simplicity.
Development became faster and more predictable. Testing became easier to manage. User journeys became more consistent across platforms, while the ongoing overhead of maintaining duplicate implementations was significantly reduced.
More importantly, the platform became easier to evolve.
Once the codebase had been consolidated, we introduced improved tracking and logging capabilities so the team could better understand user behaviour, identify drop-off points and prioritise optimisation opportunities more effectively.
We also delivered a fully native in-app checkout experience, removing the need to redirect users externally to complete purchases. That work contributed to a nomination at the Transport Ticketing Awards in 2026 and helped improve engagement, upsell performance and customer satisfaction.
For Big Bus Tours, the value of the rebuild wasn’t simply technical consolidation. It was creating a platform that could support faster iteration, better customer experiences and stronger long-term commercial performance.
In our experience, that’s often the real challenge with ageing app estates.
Businesses don’t necessarily need to throw everything away. They need to understand whether their current structure is helping the product evolve efficiently, or whether operational complexity is quietly slowing progress behind the scenes.
If your team is maintaining duplicate platforms, struggling with release overhead, or finding it increasingly difficult to evolve your app efficiently - book a discovery call with us. We’ll help you explore what a more sustainable mobile foundation could look like.