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Limit data you are working on
Use If your box spans a long period of time, use filtering, such as date filtering, if your Box spans a long period of time
Use simple JQL queries (for filters and to set up a box scope)
The more data fields to improve the performance
Use filters to limit the active data visible on the screen
Work on fewer fields visible at the same time - the more data fields (such as columns on Gantt) you show while using BigPicture Plugin, the more time it takes for the browser to calculate and render it.
Limit the maximum number of Jira issues loaded
App Configuration > Advanced > Technical info tab
Archive, close, or remove the old boxes
When a box is closed or archived, the data isn’t being refreshed
You can also Alternatively, remove the Boxes boxes you do not need don’t need
Simplify the app and box setup
Limit custom field mapping
Data synchronization
Increase the Synchronization time interval
App Configuration > Advanced > Technical info tab
live synchronization - adjust the live sync settings (decrease the live sync interval or turn off)
App Configuration > General > Live sync tab
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Switch off Fine-grained logging
App Configuration > Advanced > Technical info tab
Switch off the statistics collection
App Configuration > Advanced > Technical info tab
Field mapping
Limit custom field mapping
Jira issues and projects
Keep in mind, each additional plugin installed shares Jira's resources
Disable widgets on the issue view (should improve the loading time of Jira issues)
Archive old Jira projects
Disable the "Save task changes to Jira issue page"
App Configuration > General > Field mapping
More info on the Toggle switches page.
Browser
Make sure that your browser does NOT block caching