We start with this admission, to which everyone agrees:
None of us have a complete understanding of how CodePen works.
At this stage, some of us think that while this is true, we could figure out the parts that we don't currently know. Hopefully that stays true for a long time, but there is a good chance it doesn't. There are a ton of moving parts to a product like CodePen. Obvious things like design, front-end, back-end, and servers. But there are other huge things. How does payment work? What are all our integrations and how do those work? People things, like who do we talk to about those integrations? Who handles advertising? Understanding our financials? All the services we use, how to log into them, and what they do?
There are dependencies, both the technical and literal meaning, all over the place. What happens as we grow, or, god forbid, people leave and new people come on? All this is related to knowledge management.