starlingforge

I am poking around for a new tool to learn as a mainly backend developer and coming to the conclusion that HTML, CSS and JS seem to be yesterday's options. I'm left wondering; if you were learning today and wanted to get proficient fast, what would you learn? Typescript? React? Vue? Purescript? Bucklescript? Bulma? Bootstrap 4? (to only name a few)

I realize there are categories such as styling kits, frameworks or UI libraries, but are there any that stand out as diamonds in the rough for quality of developer life or productivity rate in their category or overall?