Dev.to is a vibrant community of developers writing articles and helping each other out. The codebase itself is open source, so anyone in the community can get involved and contribute.
Hashnode is a free content creation platform and community that allows you to publish articles on your own domain and helps you stay connected with a growing developer community.
freeCodeCamp News is a great place to read articles for developers of all levels and stacks.
Tealfeed is a knowledge sharing platform that keeps users feed informative, connects people of similar interests, and empowers creators.