Caching data during build?

[bleak lance]

I have an expensive computation I want to make in a layout that's shared between multiple pages, but I don't want to have to redo it for each page. Can I store the result in a global variable or something and reuse it for each page that's built, or is context like that not retained?

[jaunty kraken]

you can do the computation in a js/ts module and import it where its neede