The new Nonprofit Cloud (NPC) has introduced a high-performance framework for calculating donor metrics, moving away from the real-time Apex triggers used in the older NPSP model. To display a donor's total giving, last gift date, or largest gift, the system uses a combination of the Data Processing Engine (DPE) and the Donor Giving Summary object.

The Data Processing Engine (DPE):

DPE is a powerful tool built on the Salesforce Industries core that can process massive volumes of data in batches. A consultant uses DPE to:

Extract: Pull data from Gift Transactions (the records of actual money received).

Transform: Aggregate the data—summing the amounts, finding the "max" amount, or identifying the "min" date.

Write Back: Save these calculated values into fields on the Donor Giving Summary record.

The Donor Giving Summary Object:

This object serves as the "storage container" for these rolled-up values. It is linked to the donor's Account (Person Account). By storing the results here, the system ensures that when a fundraiser opens a donor's page, the summary is already calculated and displays instantly without needing to run a live query across thousands of transaction records.

The Workflow:

Clone Templates: Salesforce provides pre-built DPE templates for common fundraising rollups.

Schedule Jobs: The consultant schedules these DPE jobs to run periodically (e.g., nightly).

Display: The Donor Giving Summary component is added to the Lightning record page via the App Builder to show the fields (e.g., TotalGiftAmount, LastGiftDate) to the users.

While Declarative Lookup Rollup Summaries (DLRS) is a popular community tool, it is not a native "Nonprofit Cloud feature." The Business Rules Engine (Option A) is used for complex decision logic (like eligibility checks), not for aggregating historical financial totals.