[akoboldfrying]

Outstanding piece. It articulates the actually fundamental correctness problem of most software development:

> “given the actual set of deployments that exist right now, is it safe to add this one?”

This problem has been right in front of our faces for decades, but I haven't ever seen it laid out like this, or fully realised it myself. Which is surprising, given the obvious utility of types for program-level correctness.

I think the next big leap forward in software reliability will be the development/integration of both the tooling to accomplish this, and the cultural norms to use them. Automating this (as far as possible -- they do note that semantic drift is immune to automatic detection) will be as big a deal as the concept of version control for code, or CI/CD.

There's lots here that I need to dig into further.