50,000 investors. 99.9% uptime. And the decision to build a real app instead of a PWA.

Bloei Vermogen is one of the top 10 largest asset managers in the Netherlands, offering sustainable, low-cost investing entirely online. As their user base grew younger and more mobile-native, users were increasingly accessing the investment platform on mobile devices, and requests for a dedicated app were growing.

The initial brief was for a Progressive Web App. After a thorough review of user needs and Bloei's product roadmap, Elements recommended a ReactNative app instead. A PWA would have meant compromises on biometric authentication, push notifications, and the native feel that matters in financial services, where trust and polish are not optional.

Elements was responsible for visual design, UX, mobile development on both platforms, and the backend.

A mobile-first investment experience with biometric login

The app gives users a clear, real-time view of their investment portfolio. Biometric authentication, which would not have been possible in a PWA, was built in from the start. The interface is designed for a younger, digitally fluent investor who expects the same polish from a financial app as from any other consumer product.

A Backend For Frontend (BFF) that future-proofs the architecture

Bloei uses the Blanco wealth management platform as its core. Rather than integrating directly with Blanco from the app, Elements built a stateless BFF in Python (FastAPI, Redis, AWS ECS, Elasticache) that sits between the app and the backend. This layer handles authentication and abstracts the underlying platform, making it easy to add new features or data sources without touching the mobile codebase.

One React Native codebase for iOS and Android

The apps are built in ReactNative, sharing a single codebase across platforms. For an app serving 50,000 users with a 99.9% uptime requirement, React Native delivered the right balance of development efficiency and production reliability.

Why React Native, and why a BFF?

React Native was the right call for Bloei: one codebase, both platforms, fast iteration. The development efficiency gain is real without sacrificing the production reliability a financial app needs.

The BFF is the less obvious but more important architectural decision. Financial apps accumulate integrations over time. Building a middleware layer from day one means Bloei can add backend connections or swap data providers without shipping a new major app version. It also keeps authentication logic out of the mobile client, which matters in a regulated sector.

The project covered the full stack: UX design, visual design, frontend, and backend, delivered by one team. That breadth means decisions that would otherwise take days of handoff happen in the same room. Elements delivered design, mobile, and backend without splitting responsibility across agencies.

With the BFF architecture in place, Bloei can extend the app with personalised investment recommendations, additional portfolio views, and new integrations with financial data providers, without rebuilding.