ThiagoBarradas

public interface ITalkative
{
    void Speak(string message);
}

public interface IMovable
{
    void Move(long x, long y, long z);
}

ThiagoBarradas

public interface IMovable
{
    void Move(long x, long y, long z);
}

public interface IHuman : IMovable
{
    string Name { get; set; }

    string Document { get; set; }

ThiagoBarradas

public interface IHuman
{
    string Name { get; set; }

    string Document { get; set; }

    long Age { get; set; }

    void Move(long x, long y, long z);
    

ThiagoBarradas

public class Transaction
{
    public virtual long OriginalAmount { get; set; }

    public virtual long InterestAmount { get; set; }
}

public class CreditCardTransaction : Transaction
{ 
}

ThiagoBarradas

public abstract class Transaction
{
    public long OriginalAmount { get; set; }

    public virtual long GetTotalPaid()
    {
        return this.OriginalAmount;
    }
}

ThiagoBarradas

public abstract class Transaction
{
    public long OriginalAmount { get; set; }
}

public class CreditCardTransaction : Transaction
{
    public long InterestAmount { get; set; }
}

ThiagoBarradas

// sample enum for payment.Type
public enum PaymentType
{
    CreditCard,
    DebitCard,
    BankInvoice,
    Pix
} 

// simple factory

ThiagoBarradas

public class PaymentService
{
    public Payment ProcessPayment(Payment payment)
    {
        if (payment.Type == "credit_card")
        {
            // proccess payment with credit card
        }
        else if (payment.Type == "debit_card")
        {

ThiagoBarradas

public class PaymentService : IPaymentService
{
    private readonly IPaymentRepository PaymentRepository;

    private readonly INotificationService NotificationService;

    private readonly IBankService BankService;

    public PaymentService(
        IPaymentRepository paymentRepository, 

ThiagoBarradas

public class PaymentService
{
    // ctors
    // properties
    // etc

    public Payment ProcessPayment(Payment payment)
    {
        var transaction = this.BankService.CreateTransaction(payment);