Contract-First Collaboration Coordinate frontend/backend or service-to-service work through one authoritative, machine-checkable contract. Consumers state what they need, providers implement that shape, and both sides verify against the same artifact before integration. This skill governs how teams change a boundary. It complements , which governs what a good API looks like, and , which guards fixed bugs from returning. When to Activate - Frontend and backend work will proceed in parallel. - Two or more services exchange API payloads, events, or commands. - Field names, nullability, enums, or…