Hi I'm the person you need.
Now I'm maintaining and improving 2 ROR sites, which includes caching, speed optimization, performance controlling, that have CMS, base on ruby 2.1, rails 4/3.2.
Lets start immediate, if you can send me links to project or give me some small task, so I can show you how I can handle this.
Looking forward to hearing from you.
Best regards, Anton