fresh

They are not using their own bundler. They are using esbuild at runtime to generate bundles for individual islands when the process starts up. Then they store those files in memory in a Map. When the bundle files are requested, it just pulls the copy that was generated at runtime. Here is a link to the source where esbuild is used. https://github.com/denoland/fresh/blob/main/src/server/bundl... I personally think it would be better to bundle at deployment time so that the bundles don't need to be regenerated each time a new process starts up or on demand when a request comes in for one of the bundle files.

IMO, this post doesn't discuss the tradeoff of removing the build step. What a “build” is has been obfuscated. When you deploy an app, you now need to convert TypeScript into JS, and then the JS needs to be turned into an optimal representation for V8 to process. For example, Fresh has a “build process” whose cost is paid for by the user [1]. You want to do these things before the user hits your page, and that’s the nice thing about CI/CD. You can ensure correctness and you can optimize code. In the interest of losing the build step, a tradeoff is made for worse UX for developer experience (DX). Rather, I would recommend shifting the compute that makes sense to the build step, and then give developers the optionality to do other work lazily at runtime[2]. [1]: https://github.com/denoland/fresh/blob/08d28438e10ef36ea5965... [2]: https://ve