Just the bare minimum, favour loading speed on worst case ever (Edge/Bad 3G connections) over fancyness
- Bootstrap 4 (minified) - jQuery (minified) - Sass/Less (minified)
Backend
Solid programming languages/frameworks, avoid dynamically typed/interpreted languages, favour statically typed/compiled languages
- C++17, coupled with httpnh2, Beast or Wt framework - Java 11, with Thorntail (avoid Spring bloat) - Go - Rust