When you write something you constantly remodel your understanding through refactors and rewrites until you internalize it. By internalizing it you gain the capacity to reason about it (during critical downtime) and communicate it. An entire team that can communicate can solve problems together, from one guy's vision to products white boarding to engineering's infrastructure to UX and UI's artistry.
It boggles me we completely forgot that the world operated like this just 4 years ago
It boggles me we completely forgot that the world operated like this just 4 years ago