The sync frequency of reading data from Airtable and the rate at which Stacker writes data to Airtable.
Stacker's cache is updated every 15 minutes.
If you would like to force your portal to be updated more often than this, you can run Airtable Update. (While Airtable Update is for picking up new tables and columns from Airtable rather than new data, it will also trigger the cache to be re-filled).
Data edited in Stacker is saved instantly to Airtable. If your data is not saving to Airtable then run Airtable Update to ensure that Stacker is up to date about the structure of your base and any recent column renames etc.