Ask HN: Quickest way for an experienced developer to learn WordPress

I have a good 15 years of all sorts of development under my belt. I'm comfortable with the usual web frontend stuff, have developed webapps with Angular and VueJS, have written backends with .NET and Java and Node, etc. What I've never done is used WordPress, or any CMS at all for that matter. Now I have to take over a running corporate site and get up to speed quickly. There are so many resources (books, online courses) of dubious quality that all seem aimed at beginners. I'm looking for recommendations for learning resources that will quickly teach me the fundamentals, the workflows, the deployment processes, and so on - aimed at veterans, not beginners.