Founded in 2011, XXImo has grown from a Dutch startup into one of Europe’s most forward-thinking mobility-payments providers. Its flagship “one-card + Milo app + portal” platform allows employees to pay for – and employers to monitor – all modes of travel, from EV charging and public transport to parking, taxis, and shared cars, all on a single Visa rail.

The company keeps setting benchmarks:

• In March 2022, XXImo became the first mobility card in Europe to support Apple Pay, enabling users to travel within minutes of onboarding – no physical card needed.
• In 2023, it earned Visa Principal Member status, gaining the license to issue cards directly across the EU and accelerating its expansion.
• That credibility led to a strategic partnership with Arval in November 2023, powering the Arval Mobility Pass – a bundle of card, app and CO₂ dashboard for multinational fleets.
• In Q1 2024, XXImo became one of the first EU Visa issuers to process 100% of transactions in the cloud, going all-in on AWS. This cut latency, lowered costs, and unlocked tools like Visa Cloud Connect and Amazon Payment Cryptography.
• In March 2025, the platform achieved Visa Fleet 2.0 certification, positioning XXImo as a modern, open-loop alternative to outdated fuel cards – a critical move as clients transition to mixed ICE/EV fleets.

Sustainability is at the core. XXImo’s portal automates compliance with the Netherlands’ CO₂-reporting mandate (in force since July 2024) by capturing detailed mileage and fuel data, saving HR teams hours of manual work.

The client had three separate applications, for iOS, Android and web, each with its own codebase, release cycle, and maintenance process. This fragmentation slowed down development, delayed feature releases, and made it harder to deliver a consistent user experience across platforms.

As the product evolved, the limitations of this setup became more visible. Feature parity was difficult to maintain, testing took longer, and internal teams were stretched thin across multiple versions of the same product. Every update required triple the effort, driving up costs and limiting the team’s ability to respond quickly to user needs or market opportunities.

At the same time, user expectations were shifting. People wanted seamless experiences regardless of the platform they were using. The existing setup couldn’t meet that standard, and falling short risked losing user trust and market relevance.

To move forward, XXImo needed to simplify and modernise their application infrastructure in a way that would reduce overhead and support long-term growth.

We consolidated three separate apps into a single, robust Flutter-based solution that powers Android, iOS and web. This unified approach cut development complexity, accelerated feature delivery, and ensured a seamless user experience across all platforms.

Here is what we did:

• Redesigned the interface to create a more intuitive experience, while preserving key functionality like Google Wallet and Apple Wallet integrations from the original native apps. This helped us accelerate delivery and keep the features users were already relying on.
• Created a custom desktop UI within Flutter’s mobile-first framework. The web version demanded its own layout, behaviour, and interaction model. Achieving cohesion between desktop and mobile required precise architecture and advanced state management techniques.
• Implemented Clean Architecture and the Bloc pattern to ensure the codebase remained scalable and maintainable as the product grows. Firebase services supported authentication, messaging and analytics, while early adoption of CI/CD pipelines streamlined deployment and reduced release risks.
• Identified and resolved platform-specific differences and quirks early through rigorous testing and continuous iteration. The end result is a stable, high-performing app that feels native and reliable on every device.

We kicked off with a proof of concept and delivered in just four weeks, moving fast into full development. In about 9 months, the new Milo app was live across Android, iOS and web.

By consolidating three separate apps into a single Flutter codebase, we helped reduce development and maintenance costs, while ensuring consistent UI, feature parity and performance across platforms. Clean Architecture and Bloc patterns set the foundation for long-term scalability, faster release cycles and easier future upgrades.

The new app now serves around 30,000 users, offering a significantly improved experience compared to the previous native and web versions. Loading times for embedded web pages dropped by more than 40% – a major boost for performance, especially on the web, where the app now runs with the speed and stability of a native product.

The result is a seamless, scalable mobility solution – aligned with the client’s long-term digital strategy and built to evolve with their growing user base.

The server side:

.NET

Front end:

Flutter