Apart from dev.to:

• a couple of weekly newsletters. I love Ruby Weekly. There are more of them on other dev topics.
• books. I have a huge list to read, here's a part of it
• twitter. I cleaned up my feed, so most of it is useful in terms of learning or finding out of new stuff (I mostly use other sites to waste my time :)
• podcasts (One day I'll make a list of those I listen to)
• reading code (e.g. of opensource projects on github)
• I also like Stephen Grider's Udemy courses, but I only learn from them occasionally