Here are a few Computer Science platforms to replace social media/mindlessly scrolling with useful information.

1. Reddit - r/technology: Reddit is a social news aggregation, web content rating, and discussion website. The subreddit r/technology is dedicated to news and discussions about technology and related topics.

2. Slashdot: Slashdot is a news website that primarily covers science and technology news. It features user-submitted and editor-evaluated stories, along with discussion forums.

3. Product Hunt: Product Hunt is a platform for discovering and sharing new technology products, apps, and services. Users can submit products, which are then curated and voted on by the community.

4. TechCrunch: TechCrunch is a leading technology media property, dedicated to profiling startups, reviewing new internet products, and breaking tech news. It covers a wide range of topics, including gadgets, apps, and entrepreneurship.

5. Hacker Noon: Hacker Noon is a technology publication with contributions from the tech community. It features articles, opinions, and interviews on various technology-related topics, including programming, blockchain, and artificial intelligence.

6. lobste.rs: Lobste.rs is a technology-focused link aggregation website, similar to Hacker News. It features user-submitted stories and discussions on programming, software development, and technology trends.