Later, or as a basis for quotes, yes. For now something a lot more bare bones would help. One thing I have often found useful is wireframe sketches of what you envisage it looking like to be a good first step. For most web apps I prefer developing an MVP and improving incrementally - going down the "release early, release often" route. Very true, people do use a mix of things successfully. For example, one of my clients has: 1. A Wordpress public website 2. A static HTML page with a fairly complex JS front end app. This is their subscription service. 3. A Django back-end for 2 4. Various other bits to help run it all This sort of setup is not at all uncommon.