We have 2 types of users, regular users and merchants; both have a wallet with money and can transfer funds between them. Let's focus exclusively on the transfer flow between two users.

Requirements:

• For both types of users, we need Full Name, CPF (Brazilian Individual Taxpayer Registry), email, and Password. CPF/CNPJ and emails must be unique in the system. Therefore, your system should allow only one registration with the same CPF or email address.

• Users can send money (make transfers) to merchants and other users.

• Merchants only receive transfers; they do not send money to anyone.

• Validate if the user has a balance before the transfer.

• Before completing the transfer, it should consult an external authorization service; use this mock to simulate.

• The transfer operation should be a transaction (i.e., reversible in any case of inconsistency), and the money should return to the wallet of the user who initiated the transfer.

• Upon receiving payment, the user or merchant needs to receive a notification (email, SMS) sent by a third-party service, and this service may occasionally be unavailable/unstable. Use this mock to simulate the sending.

• This service should be RESTful.

1. Java 17
2. Maven 3.6.3 (or above)

mvn clean install

cd .\impl\
mvn spring-boot:run