[gipp]

They're just sketches. That's part of the point, and the article says that directly. The point isn't the exact shape or slope of the curves, but just their asymptotic behavior and the relationship of "correct features/day" to the other two. I.e. As long as the two curves have that general shape, then the "sweet spot" exists somewhere between 0-100%, the exact location of which depends on language, developer experience, and business priorities. The exact numbers are irrelevant to the article's point.

[ruskimalooski]

But even the asymptotes are an assumption derived from pure thought experiment.

[dwaltrip]

More realistically, it's an educated guess based off the author's personal experience as well as their understanding of the experiences of other developers operating under different constraints.

The author makes it clear that the analysis is not perfectly rigorous. There is a very wide landscape between perfectly rigorous and completely useless.

Do you think the article fails to hint at any of the fundamental dynamics of how type systems affect software development? How so?

[raquo]

I'm not who you're replying to, but for me the charts didn't make sense either.

For one example, I don't think it's a given that the green line (velocity vs % type-checked) should have a negative slope. Maybe in some cases, for some projects or some people, but certainly not universally. At least part of it would have been positive on almost all projects that I've worked on, and I'm not doing rocket science.

Then, the combined chart just looks at the amount of bug-free output, completely ignoring the amount of bug-ridden output. That latter part doesn't just get discarded, it needs fixing, and bugs that were only discovered in production are expensive to discover, debug and fix.

This is in addition to pretty much every other top level comment in this thread, a lot of which bring up important points that are unaccounted for even conceptually in the charts.