I totally agree with you. Even as a not-so-startup any more (we've been around for 11 years now). It really depends on the type of your customers: If you are se

I totally agree with you. Even as a not-so-startup any more (we've been around for 11 years now). It really depends on the type of your customers: If you are selling a specific app to them, you might more easily get away with JS only than if you are producing a page for general consumption. But, of course, if you go the JS only route (which I have done for my tempalias.com fun project last year), then you also have to keep in mind that you will be duplicating model code and dealing with two separate ORM layers: One on the server for the API itself and one on the client which gets used by the GUI controllers. Backbone can be of help there, but if you want to, say, do some validation logic already on the client without the roundtrip, then you begin duplicating logic on both server and client. So how ever you put it, going JS only is probably more work in the end, but it's also less work than going the traditional way and then bolting on a fully-fledged API because the lack of dogfooding it will cause you trouble once you get real users for it. Overall it's a really difficult decision to make and it's also quite final as changing the direction, again, means a lot of work.