Fix search results return speed (please read info below carefully before you bid)

We recently had an update done around returning results (job posts) after a job search is done on website. The results are sourced from an xml file that imposrts via ftp from an external job system. Then the site populates the results from the xml file into the website. The website is wordpress. The most current update done was adding a feature that turns job ads off on the website search results (hides them) if they are turned off via the main external job system/control panel. The issue after this update was implemented is that the results are taking too long to return to the searching user on the website. We need someone who can resolve this by simply speeding up the return rate of the results. We are open to solutions as this is the only issue with our system. Require someone that is confident with problem solving and possibly has had some type of experience with this type scenario (chron plugin, xml, wordpress, javascript/ajax). Delivery ideally need this done asap (we have lost time with no joy) - like if you can start right away that would be appreciated.