One of my pet peeves about the network “engineering” world is this: we do too little engineering and too much administration. What brought this to mind this week is an article about Margaret Hamilton about the time she spent working on software development for the Apollo space program, and the lessons she learned about software development there. To wit—

Engineering—back in 1969 as well as here in 2020—carries a whole set of associated values with it, and one of the most important is the necessity of proofing for disaster before human usage. You don’t “fail fast” when building a bridge: You ensure the bridge works first.

Sounds simple in theory—but it is not in practice.

Let’s take, as an example, replacing some of the capacity in your data center designed on a rather traditional two-layer hierarchy, aggregation, and core.