In my experience, most interface slowness in Appian comes from inefficient query calls.

My approach is:

1. Start with performance metrics

I go to the Interface Performance view to check what is taking time to load.

In the recent Appian versions, the Query Performance tab is extremely helpful—it clearly shows which queries are slow and why.

2. Identify the common causes

From what I’ve seen, slowness usually comes from:

How I improve performance

I first analyze what data the interface actually needs.

Then I optimize the query by:

I check the dependency between the queries and simplify the flow:

Move all query calls to local! variables at the top
Avoid executing queries deep inside expressions
If one query depends on another (e.g., fetch ID first → use ID to fetch more data), I combine them
Either create a database view, or
If using synced records, utilize record relationships like: recordType!Customer.relationships.person.fields.emailPromotion

This is never advisable since it causes multiple unnecessary round-trips.

I take the query out of the loop and fetch everything in one go, then loop through the already-fetched data.

After making changes, I always re-run the performance metrics or check the Query Performance tab again to confirm the improvements.