NATIVE SPEAKER! AMERICAN!
I am excellent at algorithm efficiency and would love to help you with your project.
I am an American programmer living in China, (In EU until Saturday) so communication will be no problem. Although I don't have any reviews on freelancer, here's an example of my Ruby algorithmic accomplishments:
When studying Ruby, I came up with a simple algorithm of a homework assignment that was more efficient than the textbook solution. (The problem-set writer actually requested that my algorithm be adopted as the new official solution [I helped them reduce the solution from 39 lines of code to 26]).
Anyway, I would love to chat. I can guarantee a 1-day delivery.