What about long-term maintainability of a large application? Rails has its issues there, but a body of best practices has grown up around maintaining long-lived

What about long-term maintainability of a large application? Rails has its issues there, but a body of best practices has grown up around maintaining long-lived rails apps. I wonder what the author's opinion would look like were it building the single app that is core to their business, and maintaining it for 3 years, instead of spitting out a Meteor app for a client every 6 weeks?