There are too many places to mention, but I'll list a few here:
GitHub Explore can offer you many suggested packages based on the GitHub repositories you've browsed. The algorithm works surprisingly well and learns about your habits to improve suggestions. Get your fix of open-source here.
Lobsters is the minimalist sibling of Hacker News. Its emphasis is not on major IT news but individual blogs and hobby projects. Perfect for those occasions when you appreciate someone having spent countless hours solving an obscure race condition in a homebrewed IoT project.
Cooper Press newsletters are perhaps the best-curated newsletters. Full of relevant new releases and events from different tech domains.
Pointer.io newsletter has a lot of fascinating thought-pieces on leadership, management and ways of working. This curation is even more important than Cooper Press publications. True wisdom lies not in the number of programming languages and frameworks you know but in how well you can solve problems without resorting to them.
Furthermore, I'm a big fan of Mailbrew, which allows me to subscribe to different services and newsletters to receive weekly content digests. I've set it up to deliver a daily digest every morning at 7:00 and a weekly digest every Sunday at 9:00. Perfect finite browsing with the morning coffee.
I've come to a remarkable revelation through content digests: nothing beats the slow web. It's the place where you embrace calmness—no rush to be the first to see, hear and share something. Instead, you'll take it nice and slow and enjoy a well-curated content delivered to you deliberately late. Later is better than now, and the mental health effect of the said life in contrast to a hectic refreshing of the Hacker News and Reddit is irreplaceable. Take it from someone who used to commit F5 frenzy on significant outlets and subscribed to all the good RSS feeds everywhere.
Finally, if you decide to learn something, do it no sooner than just in time.
: Don't get me wrong. RSS is still a fantastic centralised way to follow the web. It's just easy to get overwhelmed with it, too.