As someone who reads exactly those kinds of newsletters, I would say the more niche you can be the better. There's already an abundance of general tech publica

As someone who reads exactly those kinds of newsletters, I would say the more niche you can be the better. There's already an abundance of general tech publications that are mediocre, with a small number of stellar ones popping out. What tech nerds really need is something that embraces the niche tech that they use every day. Right now, the example I'm thinking of was a few years ago when Ansible became a thing and a few people started writing about it. It could really be anything from specific languages, frameworks, or methodologies.