I recently wrote a blog post on how we halved our memory consumption, and drastically increased speed, in our Ruby on Rails app just by switching to jemalloc: https://medium.com/rubyinside/how-we-halved-our-memory-consumption-in-rails-with-jemalloc-86afa4e54aa3 If anyone has any thoughts, or other tips for performance optimisation, please do leave a comment!