This. While I'm not sure I'd build a website or something with R, for pretty much anything data related R is a first choice. Even for big data on clusters or something. It's absolutely amazing at what it does. Super easy Fortran and C++ interop. Bonus that it's well enough known in academia and fields like statistics or economics.
I have. Guess I haven't tried to build something bigger with it. Seemed to me to be mostly something to share visualisations, not for building say, a whole CRUD site Rails or Django-style.
You're right - in my experience it's great for, say, creating an online calculator/simulator for something specific but it too fast becomes difficult when you started trying to add features like SSO, persistence etc.
