> Is database state?

Duh. I'm talking specifically about session_*. This data isn't magically stored in the air and if you use more than a single machine, you need to implement the SessionHandlerInterface with a solution like redis or memcached in a clustered setup. That's literally the same as using any other language, plus such map-reduce kv stores.

Since you mention that I wouldn't need php-fpm and opcache, I assume that you haven't worked at scale with php. php might be a good fit as long as you don't have any users, but this isn't true for everyone.