Shiny has a full time team working startup hours on it - it's out of beta and has enterprise support (Shiny server pro). It's come a long way to put it mildly;

Shiny has a full time team working startup hours on it - it's out of beta and has enterprise support (Shiny server pro). It's come a long way to put it mildly; and we've never had a problem using it in production. We could interface R with another language if we needed to... but we're a data-science company, and unlike many other co's or startups out there, we hire data-scientists who write features and applications directly. R makes this possible. We have an Android App as part of our services - we use RServe as the API interface so we can call R functions from the App. To your other point - web development skills are most definitely required, as are good engineering practices, and a stable stack. Shiny is just like any other framework; it takes a range of skills to create an application people want to use and pay for.