To fix an appointment booking portal

We are looking to an experienced and expert level Yii PHP developer to help us fix and enhance an online scheduling/appointment booking system. The web application was developed in Yii PHP and hosted in Azure. An ideal potential bidder should have : 1, a demo of your previous scheduling/appointment booking projects done by you or your existing team members 2, capability to make insight suggestions to improve security and UI 3, rich experience in SAAS projects with actual and real projects done by you or your existing team members, preferred in appointment scheduling software 4, past projects developed in Yii PHP What we expect you from this project: 1. test the existing running script and list down all bugs; 2. fix all of the listed bugs and ensure no major bugs; 3. carry out the enhance job scope to continuously improve the application; 4. good knowledge of SAAS and PHP 5. to start, the job review will be based on selected testing hours based on mutual agreement. PLEASE BE AWARE THAT WE WILL NOT MAKE UPFRONT PAYMENT. WE WILL GO BY FIXED PRICE AND PAY THE WORK THROUGH MILESTONES WHICH WILL ENSURE OUR DAILY OPERATION NOT TO BE AFFECTED DURING EACH STAGE. Again, please bid this job ONLY if you carry the required quality. Please indicate 'appointment booking makes easy' in the front of your message when you bid this job so we know in order to get our reply (to pursue a discussion or decline). We don't welcome a general application that will waste both parties' time and efforts. Thank you very much for your reading and interest.