Comment by xorcist

I don't think that is how it happened. Yes, there was a SCGI/FastCGI chism, but it was mostly the Python ecosystem that used SCGI and the rest of the world was on FastCGI. Unless you were PHP, in which case you were on mod_php because it was an unmovable juggernaut.

Apache had a FastCGI module early on, but it received little love and was not that widely used. For many people, FastCGI was synonymous with nginx and lighttpd because these webservers came with support out of the box (nginx later got modules just as Apache).

When PHP finally got PHP-FPM, that gigantic ecosystem slowly started moving, sometime in the late 00s, and then FastCGI really took over. Almost. Because at the same time, the cloud era started and brought the "just use HTTP bro" mindset. Amazon has always used HTTP internally since the 90s and I would guess that probably carried over to AWS?

So nowadays, PHP still being a silent juggernaut, is now mostly on FastCGI, while most other have moved to cloud era standards and use HTTP. Go, for example, matured at this time and all the tutorials use straight HTTP proxying.

Yes, FastCGI is the much more robust standard, but you will encounter friction if you use it on your cloud native application. For regular servers and VMs it is still common.