In collaboration with Slovenia’s leading supplementary pension insurance provider, we’ve built a Flutter multi-platform app that runs seamlessly across mobile and web from a single codebase.
Modra zavarovalnica is a leading provider of supplementary pension insurance in Slovenia, dedicated to creating accessible financial solutions that strengthen individuals’ social security throughout all stages of life. For more than a decade, the company has played an important role in supporting the stability of the country’s pension system while managing savings for more than 300,000 members.
Looking to expand their communication channels and give members greater control over their pension savings, Modra partnered with Infinum to design and build their mobile experience. In 2024, we built a Flutter app for iOS and Android that makes pension savings management simple and transparent. Following a successful mobile rollout, the partnership expanded with a Flutter web app. The vision was straightforward but technically ambitious: a single, unified self-service portal available on both mobile and web, with the same features, the same experience, and the same codebase powering both.
The result is a self-service customer portal where Modra members can check their pension savings in real time, review investment performance, manage documents, run tax and pension calculators, adjust their investment strategy, and manage beneficiaries — all by themselves, on any device, whenever they want.
The power of Flutter: one codebase for multiple platforms
Flutter is already a popular choice for mobile app development. Flutter Web, on the other hand, has only recently reached the maturity required for production systems at this scale. Together with Modra, we embraced the opportunity early and invested in a shared architecture designed to support both mobile and web from the start, putting Modra ahead of where most of the industry still is.
With the right partner, making a bold technology choice isn’t a risk; it’s a competitive advantage. The numbers back that up: a shared Flutter codebase made development 1.5x faster on this project. Features ship simultaneously across mobile and web, a bug fixed once is fixed everywhere, and there’s no overhead of maintaining two separate products. For a platform with 300,000 potential users, this is a long-term strategic advantage.
However, building across mobile and web from a single codebase isn’t without its challenges. UI components had to work seamlessly across very different screen sizes and interaction patterns, and the margin for inconsistency was zero. We tackled this by building a flexible component system and shared logic designed to behave naturally on both platforms, so members get the same intuitive experience whether they’re on a phone or a laptop.
To support a true multi-device experience, we had to harmonize the login flow between desktop and mobile while keeping it seamless for members. Mobile devices are personal by nature, typically used by one person. Desktop is different: the same computer might be shared by multiple people at home or at work. To account for this, we introduced multi-user support on the web app, allowing registered users to return to their own accounts from a shared device through a user selection screen.
We also layered in additional security measures: members accessing the platform from a public or shared PC are prompted through an OTP (One-Time Password) flow, and the same applies if the app has been left inactive for more than 15 minutes. The functionality of the platform is identical across devices, but the login experience is tailored to how people actually use each one.
A partnership built on trust and adaptability
Technology choices matter. But so does who you make them with. Over the years, Modra and Infinum have built a partnership that treats the product as a living thing, adapting continuously to user feedback, market changes, emerging technologies, and evolving business needs.
Modra zavarovalnica is a great example of a client who doesn’t get stuck on decisions made a year ago. They listen, they adapt, and as new challenges emerged during the development cycle, they were always willing to adjust. That’s what made this collaboration a success.
MANAGING DIRECTOR,
INFINUM
Our collaboration continues with a longer-term vision: transforming the portal from a static, screen-based interface into an intelligent, adaptive experience that supports members throughout every stage of their journey.
For a deeper look at the project, read the full case study. If your organization is facing a similar challenge, get in touch with our experts to learn how we can support you.