[auxbuss]

I've built large projects with Sinatra. I've done the same with Rails, many times. The idea that you can't build something substantial with Sinatra is hogwash.

It is not a given that Active Record -- I presume you mean the pattern -- is necessary, but AR is available in Sequel, which is the usual choice of ORM when build with Sinatra. (In addition, Sequel has myriad additional benefits over Rails' ActiveRecord, particularly if you want to use raw SQL.)

Views in Sinatra are not much different to Rails, so whatever issue you have, I'm unclear what they are.

If you end up engineering a worse Rails then, as they say, you are doing it wrong.

As I mentioned, I use both, and you can achieve the same results with either. They are both, in effect, rack stacks these days; they simply have different conventions, one more opinionated than the other.