Request for design docs

[Devanshu]

I want to understand the design, code architecture, tricks used under the hood to make it performant.
I tried searching for any literature behind the idea but couldn't find one.
I debugged through the code but I think it would take a lot of time to understand the concepts and ideas if I go this way.

My hope is that someone here will already know the whole architecture and would be able to explain/provide a link to a blog/doc.