Compile-time rules, CI gates, automated enforcement.

The messaging outbox handles the save. Doing it manually breaks the atomic guarantee. events can be lost.

await _dbContext.SaveChangesAsync();
// Outbox commits automatically

// Mutations via EF tracked entities
// MassTransit outbox commits on success

A new ID on each retry means the provider sees each attempt as a different request. causing duplicate charges.

policy.ExecuteAsync(() => {
  var key = Guid.NewGuid(); // new per retry!
});

var key = Guid.NewGuid();
policy.ExecuteAsync(() => {
  Call(key); // same across retries
});

A hardcoded "USD" breaks for customers in other countries. Currency must come from configuration.

var amount = new Money(100, "USD");
// What about GBP, EUR customers?

var amount = new Money(
  100, options.DefaultCurrency
); // From config