A developer wrote a trigger on the Contact object.

https://powerofus.force.com/s/article/NPSP-TDTM-Overview

Table-Driven Trigger Management (TDTM) in the Salesforce Nonprofit Success Pack (NPSP) allows developers and administrators to manage Apex triggers in a more flexible and controlled manner. The benefits include:

Control the order in which the code executes (B): TDTM enables you to specify the order of execution for various triggers, ensuring that triggers run in the desired sequence.

Disable specific pieces of code (D): TDTM allows you to disable individual triggers or handler classes without modifying the actual code, which is useful for debugging or temporarily disabling functionality.