Even if there are no direct instructions to follow the design principles/themes of the company, it kind of makes sense that there are some underlying design principles that all the tech blogs are adhering to (in terms of videos, animations, illustrations, code snippets).
I know about tools like [1] but they are fairly basic (afaik) in terms of visuals.
For instance, look at the amount of work in creating illustrations for [2], it seems they had someone assigned from the design team to help with these. Another example is in the blog post [3] linked in the original post.
[1]: https://www.websequencediagrams.com/, https://mermaid-js.github.io/mermaid/#/ [2]: https://www.toptal.com/ruby-on-rails/decoupling-rails-compon... [3]: https://blog.cloudflare.com/content/images/2019/06/leak2-2.p...