Let me introduce you to software for public library information systems that still thinks it's the 90s!

I used it once with althttpd. https://sqlite.org/althttpd/doc/trunk/althttpd.md

I mean, most web application backends don't implement TLS at all, under the assumption that you're using it alongside a reverse proxy. Most of the time this is nginx, but if you want to ensure no bugs are introduced on the HTTP level by the reverse proxy, stunnel is a perfectly fine option.

I use it to wrap my gstreamer tcp streams in TLS to send them over the internet, but socat can also do the same thing.