We have configured triggered sends to send a considerably large email from Marketing Cloud.Every time a customer books a ticket,the website sends us the JSON payload and we build up the email with GTL and AMPscript. Number of emails being sent everyday are greater than 5k.The emails are going fine but our data visualization tool(Kibana) reports that the response time is huge.Also the team building the email says the response time of emails rendering is between 3 and 4 seconds which is ok by salesforce standards.
Also the flow of API call is that when a ticket is booked from website,it calls our service layer which in turn calls Marketing cloud. So what and where could be the lag?How can we improve the performance? Here is the screenshot from Kibana: