Good morning Gwenn

Can you add more details about your question?

WebApp uploads to middleware the file and later it is sent to CF Instance using the API:
http://apidocs.cloudfoundry.org/221/apps/uploads_the_bits_for_an_app.html

You have many tests here:
https://github.com/prosociallearnEU/cf-nodejs-client/blob/master/test/lib/model/UploadAppsTests.js

I have tested the feature uploading large zips (applications with 300MB)

Currently,I have tested with static apps and node.js apps but I will add more tests for other buildpacks (python, java, php & ruby)