Finances Administration Program

Finances Administration Program is a personal budget planner. It answers everyday questions: how much comes in each month, where that money should go, how much you can spend today without breaking the plan, and when each goal will be met.

Logging every expense is optional. If you never enter a single one, the dashboard still works, because you can say in 30 seconds roughly how much went out in each category. Sign-up walks through five steps, from income to the budget split and the goals, and saves progress at every step.

The technical decision I like most is keeping the financial engine apart from the screens. It is made of pure functions, with no database, that handle money as whole cents and percentages that always add up to exactly 100%. Nothing changes on its own: every automatic adjustment is shown first and waits for confirmation. When a month closes it becomes a record that no longer changes, so editing the plan today doesn’t rewrite the past. And no number on screen comes from AI.

The project has 368 unit tests and 64 end-to-end tests, with over 97% coverage on the engine. The live version is a demo with made-up data: “Ver com dados de exemplo” (“See it with sample data”) opens an account with three months of history that lives only in the server’s memory.