There are two things you need to know to build your own Virtual DOM. You do not even need to dive into React’s source. Or into source code of any other Virtual DOM implementations. They are so large and complex — but in reality the main part of Virtual DOM can be written in less than ~50 lines of code. 50. Lines. Of. Code.
Continue here: https://medium.com/@deathmood/how-to-write-your-own-virtual-dom-ee74acc13060