I would be interested to see how the unicorn variant, rainbows, would benchmark in this test. Rainbows seems much better suited for high concurrency applications because it utilizes fibers for concurrency as well as worker processes. http://rainbows.rubyforge.org/ Also after looking at the sinatra app's code, I believe all requests to MongoDB are going to be blocking. For the comparison to be more fair, the ruby app should be written to take advantage of Goliath, em-synchrony, event machine, or another non-blocking ruby fiber based option. Until the ruby app is non-blocking, this comparison is apples to oranges.