I'm seeing about 1 minute, five seconds total time from purchase to order confirmation. At first I thought it might be a FirstData extension just installed, but same delay occurs on a COD Transaction. Have the usual optimzations in place such as varnish cache, javascript bundling etc. Looking at mysql console, I see magento sending statements to the database a second or two after startng the purchase, then nothing for 50-55 seconds, then a bit more activity. Looking at the profiler results at the bottom of the confirmation page, those numbers are consistent with the second burst of activity. This is a self hosted environment (Ubuntu), with the database located on a second self hosted server with an average 0.457 ms ping rtt between them. We need to identify where the delay comes from, and are open to hire consultative help on it. The only other clue is the annoying "Dotmailer connector API endpoint cannot be empty." message endlessly repeated in the exception log, even after executing sudo ./magento module:disable Dotdigitalgroup_Email. But I assume that's a red herring. Magento 2.2.3, by the way. Thanks.
