JavaScript Frameworks
Bootstrap 4 vs
Foundation
Angular 7 (Advanced)
React/Redux (Advanced)
RxJS (Reactive extensions for JS - Reactive programming - Advanced)
FireBase/FireStore (With autentification etc)
Vue.JS
Meteor.JS
Next.JS
MEAN - stack
MERN - stack
FERN - stack
FEAN - stack
GraphQL
Jest (Testing tool for JavaScript, especially for applications build with React)
Others?
ASP.Net
Python
Ruby on Rails
WebSecurity
Webservice eg.
How to access the serversite from your web-page:
WebSockets, WebService (SOAP, Rest), Ajax (XHR), SocketIO (NodeJS), Servlets ........
HTML5 and Android
Web Workers
Web Sockets
LocalStorage
CMS (Content Management Systems)
WordPress, Drupal, Umbraco, Joomla ....