"Even though the file API handles all those concerns, but it doesn't expose them to you. A narrow interface handling a large number of concerns - that makes the unix file API a "deep" module."
Both sentences here are incomplete, incoherent. I did not read past this point.
I don't know what it's trying to say. Making it a complete sentence would be a good first step. Don't try fancy stuff like this unless showing off style is more important to you than communicating coherently. In technical writing, little is more important than clarity.
Honestly the only minor criticism I can see of the OP's writing is to remove things that make it seem more disjointed than it is - dashes, unqualified pronouns (what is "it"? AWS? UNIX file system API? a particular module? all modules?). That's all.
Both sentences here are incomplete, incoherent. I did not read past this point.