This playbook contains the principles, practices, and pitfalls we associate with You Build It You Run It for digital services. The first part describes the traditional operating model of a central operations team, which we call Ops Run It. It also explains why using on-call product teams doesn't mean the end of a central operations team. A central operations team isn't the right choice for digital services, yet it remains the right choice for self-hosted foundational systems (COTS and custom integrations), which have lower deployment throughput and service reliability needs.