Hi,
I have over 12 years of professional experience as a software engineer and consultant, of which around 8 years were focused on website design and development. I've authored books on Java, C, C++ and Data Structures and Algorithms, and I specialize in PHP-based web-apps, and implementing algorithms in Java/C++/Python.
Given that your code is currently in PHP/jQuery and relate to filtering, are you open to a Python based solution? I can convert the code to Java with equal ease, however, recommending Python due to its better filtering capabilities, and compatibility between 3rd party libraries (such as for Excel handling) across PHP and Python.
I believe I can deliver high quality code suiting your needs. Looking forward to working with you on this project, and establishing a basis for an ongoing professional relationship.
Thanks,
Gaurav