Software engineering blogs
github.com
github.com
Don't be fooled by engineering.company.com sub-domaines, most of them only scratch the surface of technologies and most of the time have unnecessary marketing noise.
If you really want to learn some technology, I advise against corporate blogs (except if your goal is actually to be aware of what technologies are companies using)
If you work on a small engineering team and want to broaden your knowledge of technologies you might want to use, reading about approaches that larger companies use is a great source of information. Most cutting edge software engineering (not computer science), occurs in technology companies. So if you ignore "corporate" engineering blogs, then you are hugely limiting your exposure to how software engineering works in the real world.
Of course the companies are not blogging about everything, but that is irrelevant. Your choices are either a) not learn anything or b) learn stuff that might be dated (but probably also battle tested and rock solid).
And I think you are way off with the advertising thing. The reason most companies make these engineering blogs is to attract engineering talent, thus their incentive is to post cool stuff which is interesting and exciting. Look at Etsy's great engineering blog [1] which I've personally learned quite a bit from. Read a few posts... they aren't trying to sell arts and crafts.
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1: https://codeascraft.com/, in the OP's list
Edit: Seems the OP did add it.
Not interested in opening up that debate, but I thought based on the title this would be something else.
Too devops-y?
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