TechniqueSoftware engineeringVideo located
In a distributed system every request may arrive twice, so make the second one harmless
Design every retryable operation so that doing it twice has the same effect as doing it once; the network will test this for you.
System design interviews, payment and order systems, and any API that a client might retry.
From Build a Robust Payments Service Using Idempotency Keys · Arpit Bhayani