The 12.1 factor approach prefers locality over fully integrated environments. Doing so promotes fast and independent iterations on discrete services using automated tests to verify correctness. End-to-End issues that may have been identified with a fully integrated environment with dev/prod parity should be pushed downstream in the deployment pipeline in accordance with test pyramid principles. If a regression is identified, then it may quickly addressed by adding tests to the relevant service’s test suite.

Topics Mentioned in the Show

• The 5 Ideals 
• The Unicorn Project
• Practical Test Pyramid
• Hexagonal Architecture
• Team Topologies
• My Talk at WrocLove.rb 2014 on Software Architecture, Object, Roles, and Boundaries
• Bounded Contexts & Domain Driven Design

Resources

• The 12 Factor App
• Jay Kutner on the 12 Factor App via SE Radio
• My Review & Analysis on The DevOps Handbook
• My Review & Analysis on Accelerate
• Software Development in 3 Principles & 4 Metrics

Books

• The DevOps Handbook by Gene Kim, Jez Humble, John Willis, Patrick Debois
• Accelerate by Nicole Forsgren, Jez Humble, Gene Kim