In enterprise instances, the number of custom fields and field configurations tend to increase rather fast, easily reaching more than a 1000, and JIRA struggles to handle this, especially in maintaining caches and performing permission checking.

There are some improvements that could be made to better scale on this.

Longer persistence of caching

Populating caches is expensive, as it locks out multiple operations that depend on it. Currently, most of our field caches expire every 30 minutes.

Expensive permission checking

High memory usage