The Four Types, in One Paragraph
Before rules modify the record before it’s written. After rules do work post-save. Async rules run in the background (non-blocking). Display rules run when the record loads. Pick by what you need and when — not by what’s convenient.
Performance Traps
A business rule that runs on every Task update across all Task subclasses is a production risk. Scope rules tightly: conditions, tables, applicable events. A rule that fires 10,000 times a day does not belong on a hot table.
Async Is Underused
If the work can wait a few seconds, make the rule async. It unblocks the user transaction and pushes load off the synchronous save path.
Use Script Includes for Logic
Business rules should be thin — the logic belongs in a Script Include. Keeps logic reusable, testable, and reviewable. A 400-line business rule is a smell.
Governance: Who Owns What
Maintain a business rules inventory per app scope. Orphan rules (no owner, no documented purpose) accumulate. Review quarterly; retire ones that haven’t fired in 90 days.