"Making Impossible States Impossible" by Richard Feldman

What this video covers

Richard Feldman's elm-conf talk on designing models so that bugs from impossible application states cannot occur, using Elm's compiler and types. It demonstrates techniques for making invalid states unrepresentable.

Why it surfaced in Hacker News

HN repeatedly recommends it as a talk that changed how people model data, with ideas that apply well beyond Elm to any typed language.

Recommendation context

Short excerpts from positive mentions. Open the source to read the full Hacker News discussion.

“Really changed how I think about programming.”

“has given an absolute gem of a talk”

“has really changed the way I approach dealing with data in my code and was very insightful.”