Optimise current script that updates XML product feeds

Optimise current script that updates product feeds from affiliate networks like [login to view URL] The current feed runs well except when it comes to large feeds (currently only two) in number. This project's scope is to optimise the script which should not only enable the current feeds to run smoothly but also future amendments or additions (from the same networks) Please bid only if you have experience with such scripts and if you are serious about customer care (in case of issues)