Do you have cache disabled?

Also, how long does your actual bundle time take? For small projects, I actually get away with just triggering the bundle command when appropriate files in the project change. I highly doubt it would work for you, but if you're spending 10 seconds waiting for stuff to come in over the network, and your bundle command runs in 5, you could just do that instead, and actually work with the bundled code (and generated source map)

Looks like I'm not the only one who thinks it's sometimes a good idea: https://60devs.com/optimizing--default-jspm-workflow-with-gu...

I think JSPM should stress the part about bundling. It's the second person that I see who says "JSPM is slow" and the reason behind this slowness is that they didn't bundle the files or bundled them incorrectly.

We do the same in our project: we bundle all the 3rd party libs when they change, so only our own code gets retranspiled on each page load. During deployment, we bundle all the JS in a single bundle (which is good for us, as we don't have too much JS in that project).

Any chance you can go into detail how you bundle your 3rd party dependencies separately? I have tried that, without much luck.

For me it's like this:

> jspm bundle app//* - [app//*] js/tmp/dependency-bundle.js --inject --no-runtime

That tells JSPM to bundle everything except your application if your app lives within the app/ directory.

> jspm bundle babel js/tmp/bundles/babel.js --inject --skip-source-maps --minify

This tells it to bundle the Babel dependencies which aren't considered in the above.

Using bundle arythmetic.

jspm bundle src/app.js - src/[/*]

This will tell jspm to bundle src/app.js with all its dependencies, excluding everything in the src/ directory. This will result in JSPM bundling only your dependencies.

You should check out StealJS which is a fork of JSPM[1]. The biggest difference between StealJS is that it uses NPM so you don't need a separate package manager tool. Aside from that, we have built in hot module swapping so dev can be really fast (less than 200ms per change usually). Also on the roadmap is caching using Service Workers.

[1]http://stealjs.com/

We solved this with https://github.com/jackfranklin/jspm-dev-builder

It's so fast now.

SystemJS is dog slow if you load all your JS upfront. When mostly lazy loading, SystemJS performs reasonably, at least in my case.