1. The problem — ImpressãoMais3D
A 3D printing store sells two very different things through the same cart: a catalogue part, and a part that does not exist yet, uploaded by the customer as a 3D file. Both run through quoting, production, delivery and in-store pickup.

2. The constraints — ImpressãoMais3D
Selling a part nobody has seen yet. The customer must trust the result before production starts — and once printed, there is no undo. Add an order that crosses quoting, artwork, payment, production and delivery, each with its own rules, and the real risk stops being technical and becomes commercial: printing the wrong thing costs material and time.

3. The decision — ImpressãoMais3D
The uploaded file (STL, OBJ or 3MF) is rendered in the browser with React Three Fiber and becomes a proof the customer approves or rejects. Production stays locked until approval — turning a conversation about expectations into an auditable record.

4. The solution — ImpressãoMais3D
A 3D visual proof generated automatically from the uploaded file and rendered in the browser, which the customer approves before anything reaches the printer — approval is an explicit gate in the flow, not a notice. Underneath, a modular monolith of twenty bounded contexts where module boundaries are enforced by tooling, not by convention.

5. The lesson — ImpressãoMais3D
Each module has domain / application / infrastructure / presentation layers, and the domain layer imports no Supabase, Next or React — enforced by an ESLint rule (no-restricted-imports), not by discipline. Modules only talk through the application layer.
