Exam Plat-Arch-204 Topic 4 Question 109 Discussion

Achieving "exactly once" delivery and high reliability in a critical finance integration requires an asynchronous pattern that provides better control and error handling than standard @future methods. Queueable Apex is the architecturally preferred solution for this scenario.
Queueable Apex offers several advantages over @future methods:
Stateful tracking: Unlike @future, Queueable jobs return a Job ID, allowing the system to monitor progress and verify completion.
Chaining: You can chain jobs to process records sequentially, which helps maintain the integrity of order and line item data.
Complex Data Types: Queueables can accept complex objects as parameters, making it easier to pass high-fidelity order data than the primitive types required by @future.
Option A is unreliable because it relies on human intervention for retries, which is prone to error and does not scale. Option C is less desirable because @future methods cannot be monitored as effectively and lack the ability to return a Job ID for subsequent tracking.
To ensure accurate invoicing, the architect should design the Queueable class with a custom error handling process that includes logging failures and a retry mechanism. Additionally, to prevent duplicate invoicing, the finance application should be designed with an Idempotency check (using a unique Order ID from Salesforce) to ensure that if a retry is sent, the system recognizes the duplicate and does not create a second invoice. This combination of Queueable Apex and idempotency provides the highest level of reliability for critical financial transactions.