I am running a REST API server. How do I benchmark (tried ping, traceroute, pingdom) and improve speed?

My infrastructure is: gandi domain, aws dns, route53 api.domain cname pointing to a to self-signed ssl-enabled elb (having 1 elasticbeanstalk instance). Elasticbeanstalk instance is docker-based. That means nginx forwards to docker instance. Docker instance has nginx which serves static files, and reverse-proxies to golang (fastcgi to port 3000). Data is stored on Amazon RDS and is accessed using go-sql-driver.

It looks overly complicated, what is the best way to simplify?