Looks like you are targeting devs, so content is king. Auth is a tough market to get started in. The main issue will be "why should I trust your small outfit over a large and established product?"

See the skyscraper technique mentioned here: https://boringseo.org/

Here are some others I like

https://developers.google.com/search/docs/beginner/seo-start...

https://mailmeteor.com/blog/seo-for-dummies