I've been a long-time user of Sinatra as well as Rails. About 8 years ago or so I decided to move all of my sites onto Sinatra and made a simple file-backed CMS that has scaled quite well over the years.
The drawbacks of the approach have been having to write a lot of methods and classes from scratch to handle certain processing data (there is no actual database) but the end result has been something quite bulletproof and scalable to a point, and the experience implementing those features (like TLS, sessions, helpers, etc) has been quite valuable.
However, my needs are starting to grow and I think soon we will have to move off of the old framework onto something new as our business requirements grow more complex.
The drawbacks of the approach have been having to write a lot of methods and classes from scratch to handle certain processing data (there is no actual database) but the end result has been something quite bulletproof and scalable to a point, and the experience implementing those features (like TLS, sessions, helpers, etc) has been quite valuable.
However, my needs are starting to grow and I think soon we will have to move off of the old framework onto something new as our business requirements grow more complex.