This document discusses continuous delivery and the missing parts of implementing it fully. It begins by defining continuous delivery as building, testing, and releasing software faster and more frequently. It outlines eight principles and four practices of continuous delivery. However, it notes that while developers may implement continuous delivery, the operations side is often missing parts like configuration management, immutable infrastructure, logging, metrics, monitoring, orchestration, and disaster recovery. A maturity model for continuous delivery is presented, and benefits like agility, faster recovery, more experimentation, and better products for customers are discussed.