This paid membership site provides tons of short video lessons for front-end developers.
The quality differs a bit. Some courses are quite thorough, but some just scratch the surface.
For example, Up and Running with TypeScript only offered a glimpse of what TypeScript can offer.
The Cycle.js Fundamentals course by framework creator André Staltz gives you a good understanding of what Cycle.js has to offer and how to use it.
Egghead.io also comes with lots of free resources which they call [Community Resources]https://app.egghead.io/community/resources().
There are also some free courses for React, i.e. Kent C. Dodds’s The Beginner’s Guide to React.
I encourage you to check this site out, and at least take a glimpse at the free courses.