Immoptimiz

The idea came from my cousin, a real-estate agent at the time. His clients who bought property to rent it out kept asking him the same question: how should I declare this income, and which tax regime is best for me? He could not answer, so he sent them to a chartered accountant.

As the question came up more and more often, he saw a real opportunity. He trained in real-estate taxation in Paris, then met several chartered accountants. Together they built an Excel file that compared the French tax regimes for rental income (unfurnished letting, LMNP, LMP, SCI under income tax or corporate tax) based on each client’s own situation. He could finally recommend the regime that made the investment most profitable.

Excel does not scale

The file worked, but it could only serve one person at a time, sitting at a computer. My cousin came to present the project to me and asked whether it could become a web or mobile app. That is how Immoptimiz was born.

The whole platform

I built the entire platform:

• the marketing site, with the simulator and the free tax study
• the API, which holds the calculation engine and all the business logic
• the client back office, where investors follow their study and their filings
• the accountant back office, for the chartered accountants who process the files
• the admin back office, to run the business.

On the backend, a .NET Core API in C# built with DDD, CQRS and MediatR on PostgreSQL, with a strong focus on clean code. On the frontend, Angular and Flutter. Everything is hosted on Railway.

The first clients came in, then more, up to 188 today.

V2 and e-invoicing

We recently shipped a V2 that refreshes the apps, both visually and in usability. We also used it to add e-invoicing support: Immoptimiz complies with the French e-invoicing reform.