The most important outcome for me when I did this (for 6 months) was my own webapp generating infrastructure, modules for common things with a whole lot of scripting to integrate 50-80% of all features (payments, chat, onboarding flows, landing page templates, dashboard templates, checkout flows, profile creation, etc.) depending on the app. Of course, building this infrastructure took about 4,5 months to put together and is an ongoing project, but was only possible after building 7 webapps in a row. I'm confident I could get a serious looking prototype for pretty much any webapp idea in less than a month, and depending on the app maybe less than a week.<p>(As an aside, if you're going to do this, you should also get Sketch and learn how to do graphics.)<p>I built all my infrastructure, modules, and scripts on top of Rails, and I may be biased, but I do credit my success with this to the ease, simplicity, and maturity of Rails. Popularity debates aside, is there any better framework for rapid prototyping than Rails?