Part IX: How to Use This Knowledge
Practical playbooks for every role.
Audience: Everyone
Everything so far built the model; this Part spends it. Four playbooks, one per seat at the table: the founder deciding what deserves attention at each stage, the operator keeping the system healthy every morning, the architect designing infrastructure that stays correct under failure, and the consultant turning the whole mental model into a practice — engineering, payments advisory, and AI-powered payment operations. Read your own chapter first, then the seats you sit next to.