Drupal module integration with existing code

Hello developer, We are looking to partner with Drupal experts having excellent knowledge in PHP, AJAX, and CSS. We have a pre-beta website developed in PHP/MySQL, and would like to transfer one of its key features onto our Drupal site. The developer is to carefully study and understand the functionality of our online tool (documents and functional specs will be provided). Then, from our existing PHP/MySQL website extract the specified calendar-tool and its related functions, and integrate this into our Drupal framework as a fully integrated user module and it's functions controlled in the respective Admin Panel. - Full seamless integration of PHP/MySQL code with our Drupal site. - Fully functioning calendar tool in addition to all related preexisting networking functions - Incorporate the look and feel of the module that we require. - Developer is to perform their own testing with due diligence and ensure that the site is completely bug-free and fully compatible in conjunction with client testing. - Developer is to be in active communication with client during UAT period in order to resolve bugs in a timely manner. - Developer is to provide 90-days of bug-support following sign-off of deliverable (in the case that any issues overlooked during UAT testing arise afterward). Bugs are to be fixed and addressed within 72 hours maximum. - This job is on a work-for-hire basis where the finished product (code/script) delivered is owned by the client (us). - Developer must agree to sign an NDA agreement before accepting work. - Payment terms: 10% upon acceptance of, 30% upon working-integration ready for UAT, 30% upon client acceptance of deliverable (end of UAT), and 30% upon completion of the specified bug-support period. Thank you!