Backend

The part of an application that runs on a server, handles data storage, business logic, authentication, and communicates with databases. Users never see it directly.

The backend is what makes apps dynamic: it stores user data, processes payments, sends emails, and runs all the logic that can't safely live in a browser.

When a user signs up on a founder's app, the backend validates the email, hashes the password, creates a database record, and sends a welcome email, all invisibly.