Building a Swiss Open Banking & Budgeting App

Secure Cloud Infrastructure and Cross-Platform Agility

As Co-founder and CTO, I was responsible for the entire technical vision, architecture, and team execution. I led a dedicated engineering team to build a highly secure, scalable, and responsive application from the ground up, selecting a modern tech stack that prioritized both rapid development and enterprise-level reliability.

Cross-Platform Mobile Experience with React Native

For the user-facing application, we chose React Native. This allowed us to maintain a single, agile codebase while delivering a native-feeling experience for both iOS and Android users. We focused on building an intuitive, visually engaging interface where users could easily link their bank accounts, set granular budgeting goals, and view automated categorizations of their monthly spending habits.

Robust Backend and Data Parsing with Nest.js and GCP

The core engine of the platform was built using Nest.js. This progressive Node.js framework provided the strict architecture and TypeScript foundation necessary to handle complex financial logic and heavy API traffic. The backend was responsible for orchestrating the open banking connections, securely fetching transaction payloads, and running the categorization algorithms.

To ensure maximum security and scalability, we hosted the entire infrastructure on Google Cloud Platform (GCP). We utilized GCP's advanced security protocols, encrypted databases, and scalable microservices architecture to ensure that user data was never compromised and that the app remained performant even during peak daily syncing periods.

A Technical Success and a Strategic Pivot

Under my technical leadership, the team successfully engineered and launched the core product. The app seamlessly connected to the Swiss banking ecosystem, successfully parsed complex transaction data, and delivered a highly praised budgeting and insight-generation experience to our users. We proved the technical viability of a unified open banking platform in a notoriously strict regulatory environment.

Navigating Startup Dynamics

While the technology was a resounding success, the realities of early-stage startup building often involve complex human dynamics. As the platform matured, significant strategic disagreements emerged between myself and the CEO regarding corporate governance, the long-term vision of the company, and overall management styles.

Recognizing that a deeply aligned founding team is critical for a startup's long-term survival, I made the difficult but professional decision to step down from my role as CTO and exit the project. This experience profoundly sharpened my technical architecture skills in the FinTech space, while also reinforcing the critical importance of absolute alignment on company culture and operational strategy at the executive level.