These are not always necessarily useful on the job, but are somehow thrown around the industry. If you're someone who already knows HTML, CSS, and JS fundamentals, and are trying to get up to scratch like me... maybe you will find it useful. I also don't claim to know all the following areas and I lifted these from job posts, chats with peers and hearsay while in junior roles. Take it with a grain of salt.
Aditya Y. Bhargava's "Grokking Algorithms" has been particularly helpful in learning the first four concepts.
If anyone has anything else to add or wants to correct my assumptions of what's fundamental to a dev gig, feel free to add!
Gitlab and Git Flow
BEM and modular CSS
Test Driven Development
Virtual machines and containerization
Web sockets/Web hooks
"Nice to haves":
D3.js or WebGL
Deployment experience with Amazon Web Services