What I am expecting is a Linux administration expert to look into the system configuration and also into the PHP code itself to see where performance can be improved. Since the current configuration has 8 Gb of memory and 4 VCPUs, I really can't imagine why it is so slow. I have copied the existing image and placed a duplicate into service for testing for this project. I will allow full root access via SSH to the server.
The deliverables for this project will need to be: (1) specific "findings" (root causes) and explanations as to what can be improved, and (2) specific recommendations for changes. The recommendations must be tested by the freelancer *and* documented in a way that we can apply the same changes ourselves to the production environment.
The winning freelancer will have an opportunity to bid on several more projects very similar to this one--if he or she does an excellent job in helping us.