[This note was first published in my newsletter (23 November 2025. One can subscribe to the newsletter here.]
I might sound like a broken record, but the CloudFlare outage is one more example of the consequences of the software industry making the wrong technical choices.
Where were the contracts? Rust, by all accounts the language of the code at the source of the problem, is one of the fashionable choices at the moment but does nothing to provide what serious software engineering demands.
In simple terms, an invariant was violated: a change to database permissions resulted in a “feature file” growing out of proportions. In Eiffel, you express the consistency constraints as invariants, you monitor them, and catch violations. Simple as that.
Just in case you did not know, you can find everything you will ever need to know about invariants, Design by Contract and Eiffel at eiffel.com.
