I’ve been tasked with maintaining our online stuff (some websites, some backend API for our app, a basic admin page for in-app feedback) It was originally writ

I’ve been tasked with maintaining our online stuff (some websites, some backend API for our app, a basic admin page for in-app feedback) It was originally written in PHP over 10 years ago with bits and pieces added. Over the years it's gone between hosts, Linux distributions, and many PHP/Apache versions. I think it only broke due to a PHP depreciation once. So if you want longevity, I'd say PHP is the best option, even if you just use PHP to generate a static site.