ServiceNow Best Practices · LessonReviewed by Neelima, ServiceNow Architect · Updated · Published · current release · guidance
ServiceNow Scripting best practices
Write server-side code that is fast, safe and upgrade-friendly.
Quick answer
ServiceNow scripting best practice is five habits: query only the fields and rows you need and add setLimit(), never run a GlideRecord query inside a loop over another query, use GlideAggregate for counts and sums, centralise reusable logic in Script Includes rather than copied business rules, and prefer configuration and out-of-the-box features to stay upgrade-safe.
Follow these to keep code performant and maintainable.
- Query only the fields and rows you need; add
setLimit(). - Never run a GlideRecord query inside a loop over another query.
- Use
GlideAggregatefor counts and sums. - Centralise reusable logic in Script Includes, not copied business rules.
- Prefer configuration and out-of-the-box features to stay upgrade-safe.
- Guard against recursive business rules.
- Cover critical logic with ATF tests before promoting update sets.