Re: Nuts to them all. MongoDB is web scale.
I've not used jdbc. With C, or even Python, it's a bit messy but doable for a few 10s of concurrent users on a LAN server. The good news is that it is extremely easy to port up to PostgreSQL if the application does grow.
For most web applications the db talks to a single user, the web server. The post indicating hundreds of SQL statements per second on the SQLite site was made in 2015, I would imagine that it would have gone up since.