Application PHP programming is required

It is necessary to rewrite (correct) the existing "curve site" in the correct way. The engine is a self-written (jQuery script is present) PHP programming language (who did it is not known). MySQL database. The site is written with crutches and errors holes. In the company conducted an audit of the site and came to the conclusion that there is no point in developing the site since the weak foundation. You need a specialist who can correctly correct (rewrite) within a month. The site has never been monetized, so it has a small budget. (No serious errors after the site audit)