Next.js 16.4

What I tested

Two production apps on 16.4: one migrated from the previous caching model, one greenfield with Cache Components on from the first commit. I was looking for whether the new model removes the class of bug where a page is static when you expected it to be dynamic.

What worked

• Cache Components make the caching decision explicit at the point where the data is read, so the answer lives next to the code instead of in a mental model.
• next upgrade --agent gives upgrade guidance that is specific to the version you are on, which is far better than reading a changelog and guessing.
• Bundle size came down without me doing anything clever, and Turbopack's shared runtime cut the duplicate module problem across routes.

What did not

• The migration is not mechanical. Caching changes need to be justified one at a time, and the tooling cannot tell you whether your product needs a fresh read.
• It wants to be the framework for everything now. That is fine for a product app and less fine when you only need a few routes and a build step.