Have you ever worked with transactions where multiple requests must be executed as a single unit or rolled back completely?

Yes, I have worked with transactions when multiple requests need to be executed as a single unit. This is important for ensuring data integrity — either all operations succeed, or in case of an error, all changes are rolled back.

In the context of DevOps, this could be, for example, during deployment automation, when several steps need to be performed sequentially, and if a failure occurs, the system should be reverted to its original state.

In databases, transactions are usually implemented using commands like BEGIN, COMMIT, and ROLLBACK. An example in SQL:

BEGIN TRANSACTION;

UPDATE accounts SET balance = balance - 100 WHERE id = 1;
UPDATE accounts SET balance = balance + 100 WHERE id = 2;

-- If both requests are successful
COMMIT;

-- If an error occurs
ROLLBACK;

In infrastructure code, similar mechanisms or tools supporting transactions can be used, such as Terraform with state management and change planning, where changes can be rolled back in case of errors.