shinyloadtest and performance


I want to inderstand and explain the session and latency graph returned by shinyloadtest package.
I pushed to production a shiny app test with shiny server opensource and want to simulate performance if many user connection.

I simulate 30 users connecting to the the app.

I choose to test this application in my server :

Here the session graph :

For me, shiny server open respond to requests one by one, so the grey color is the time where shiny server will respond to the 29 others users ?

Here the latency graph :

Any help to interpret this graphs will be appreciated