At Product level, once a global change needs to be performed, it might have a financial impact (interest change in my example). The scope of these changes should be defined, only one as been requested so far.
In the example of a global interest change increase/decrease (which might be directly related to Central Bank changes), our Customer will have a process to communicate this change, amend the contract and agreed on a date for this change to be effective. Most of this process is manual because not much predicable nor standards for all cases.
it has happened in the past, due to manual changes, that the product was updated couple of days after the effective date contractually agreed. Backdated those changes manually is a lot of manual work again, with a high risk of mistakes.
At Product level, for Deposit product initially (to see if if makes sense for Lending as well), have the possibility to apply the financial changes (booking) with a backdated effective date and have an automated updates of all the position related to that product (wide changes apply to all customers)