this is a very common question, and it is a great opportunity for Qlik to provide some self-service information to help developers be able to improve mashup performance. I am looking for the same information
I'm afraid it is very hard to answer. Since there are so many things you can do with mashups there are also many mistakes you can do that makes it slow.
However a first step is to check thats it is the mashup that's slow and not the app. If it makes just as long timme to open the app in Sense Hub your problem is with the app.
Second problem to check is that you don't load too many objects at startup. Don't load objects until the user
