The complexity of delivering enterprise-grade software, especially as-a-service, keeps getting more sophisticated even with the large set of open-source and commercial helper tools. Every single commit by the developers must go through a large group of checks to ensure that it won’t break or regress reliability, resiliency, security, compliance, privacy, performance, accessibility, operability, etc. Being a developer in such an environment is not a fulfilling role at all. Full stack, as a notion, is not applicable to large-scale systems and enterprise software. We are introducing a new, horizontal, approach called “full-spec software” where each layer of the system is architected, designed, and built with the long list of enterprise readiness attributes listed above. Making full-spec software a reality requires a new organizational construct called “platform engineering.”