Nintex workflow cloud is quite fast

Nintex workflow cloud is quite fast, my testing workflow has only one step, sending a email to my account. I kick start the workflow by external restful api call, i get the email within 5 seconds. Sending and receiving email consume time, so i guess nintex cloud just need 1-2 seconds to start and finish the workflow, which is very fast. The workflow designer is pretty smooth, open up a complex workflow (with > 40 activities) just need 2 seconds, a great improvement if compare to office365 nintex designer.