Disclaimer: We sell TestNow.
We created a load testing tool called TestNow on Digitial Ocean. TestNow creates 100s of small machines with a different browser in each machine. The machines we have created using normal username/pwd were compromised by some attacker. Hence DO had stopped us. So we created machines using ssh keys. We also used fail2ban. Our platform installs some testing tools and test sets on each of these newly created machines based on the components running on them, etc. gather reports from each of these components and different browser versions, consolidate those reports, and if all tests have passed, we destroy all these machines (to keep costs low). Takes us around 1 hour to create 100 small machines. All our load does not get distributed in parallel by DO to create servers within 55 seconds.
Hope this helps.