What would you do to convince a large audience, who has little context, to use your solution to a problem? One way is to write a design document, which helps scale technical communication and build alignment among stakeholders. The wider the scope of the problem, the more important alignment is. A design document achieves this by addressing three key questions: “what is the goal?”, “how will we achieve it?” and “why are we doing it this way?”. This talk will cover identifying your audience, effectively writing answers to these questions, and involving the right people at the right time.