General

Web Languages

FreeCodeCamp Javascript Course

Linux

Bash Academy

Cloud

Altered Security - Azure Pentesting	Cloud Resume Challenge	https://pwnedlabs.io/

Reverse Engineering

https://revers.engineering/applied-re-accelerated-assembly-p1/	https://github.com/SkyPenguinLabs/REplay

Cryptography

https://cryptohack.org/