In principle, deploying PHP is extremely easy. Just log into the FTP account of the hoster, upload your files, done. Before I deploy, I want to create a test environment locally such that I can quickly see what my changes actually do before uploading it.
A while ago, I had an intriguing conversation with somebody who disclosed some secrets about PHP. He told me that he does not use functions but rather include files, since a function file would have to be included and since something has to be included anyway, there was no need for the function after all.