I'm not sure about SRE specific or CI specific writing but at risk of answering another question, here's what comes to mind for me.

In the Operations space my favorite writer is Charity Majors, although a lot of what she talks about isn't OPs specific:

https://charity.wtf/

Rachel by the Bay is also great:

https://rachelbythebay.com/w/

Totally not related, but Phil Eaton's posts on how databases work are super interesting and lack fluff.

https://notes.eatonphil.com/

In terms of CI and builds, I try to write some on this topic for the Earthly Blog. My Bazel article was recently on Hn. Here are my posts:

https://earthly.dev/blog/authors/adam/

Warning though, I also write about lots of other stuff. Are there specific CI topics you'd like to see covered?