Divido

The problem

Shared expenses quickly become difficult to track when different people pay for different things. The challenge is not only recording expenses, but modelling participants, payments and splits in a way that allows balances to be calculated reliably.

The solution

I am developing Divido as a mobile app where users can create groups, manage members and register shared expenses. React Native and Expo are used for the client, while Supabase provides authentication, APIs and a PostgreSQL database. Access is controlled with Row Level Security so users can only access groups and data they are authorised to view.

My responsibilities

• Responsible for the product concept and user flows.
• Developing the frontend and data model.
• Implementing authentication and database architecture.
• Working with API integration and access-control policies.
• Implementing form validation and version-controlled database migrations.

Technical implementation

• Supabase Auth is used together with a separate profiles model for application data.
• PostgreSQL Row Level Security controls access to groups and memberships.
• A PostgreSQL function creates the group and its initial membership atomically within the same transaction.
• React Hook Form and Zod are used for forms and validation.
• Expo Router is used for navigation.

Result

The project currently includes a working mobile foundation with registration, login, user profiles, group creation and group member views connected to a production-oriented backend. The next stage focuses on invitations and the core expense, split and balance models.

What I learned

• Working more production-oriented with mobile development and backend architecture.
• Separating authentication from application data and avoiding reliance on the client for security or critical business logic.
• Working practically with PostgreSQL relationships, RLS, database functions and atomic operations.

Technologies

• React Native
• Expo
• Expo Router
• TypeScript
• Supabase
• PostgreSQL
• Supabase Auth
• Row Level Security
• React Hook Form
• Zod