Software Engineering

Given a Dependency Relationship, like:

• A -> B -> C

  (depends-on A
              (depends-on B
                          C))
  

• with "->" signifying "depends on" ..
• upstream and downstream helps relatively address dependencies.
• A is an upstream dependency of B
• B is an upstream dependency of C
• A is a transitive upstream dependency of C
• A (C) is the most (least) upstream dependency
• C (A) is the most (least) downstream dependency

• Development
• Testing
• Production

• https://12factor.net/

• https://en.wikipedia.org/wiki/Idempotence
• https://hackernoon.com/the-idempotence-principle-in-software-architecture