NOTE: Developers probably don't need to read this chapter.
A vital part in the success of open source software development is having a clear vision and direction for the product design. Failure to pull that off is a leading factor in the stagnation and mediocrity of many software projects.
The Graphite project's founder and its principal product designer, Keavon, is in charge of maintaining and evolving the product design to ensure cohesion within the development process. This ranges from building the user interface design system and content layout as a mockup before it's replicated in HTML/CSS, to determining user workflows, to translating high-level goals into the constraints and requirements of specific features for the development team.
The hardest part is translating an always-evolving network of ideas and thoughts comprehensively into written form in order to communicate the big (and little) ideas to collaborators. As the product develops, the design grows alongside the code and real usage of the developed features helps bring clarity to what's planned next. Since the design process never stops evolving, any attempt to write it down is inevitably doomed to become out of date. And the multitudes of mental state can't possibly all be written down.
Despite the challenges with documenting design, this chapter aims to provide a living catalog of ideas surrounding some topics in the product design process. It won't be organized, nor complete, nor will it be always current. The best way to seek clarity about a topic is asking Keavon about it on Discord. This chapter is optional reading and is likely of minimal relevance to most code contributors.