https://blog.acolyer.org https://blog.acolyer.org reviews a computer science (scientific) paper each week day and gives decent insight. Not really an alternativ

https://blog.acolyer.org https://blog.acolyer.org reviews a computer science (scientific) paper each week day and gives decent insight. Not really an alternative to HN, but the comments are usually high standard and often highly technical. As others have said, HN is good for serendipitous discovery of topics you may not have been looking for. However it can sometimes be an echochamber of superficial/similar comments.