Finding Rails startups with strong product research emphasis

I landed at learning Rails (coming from Haskell, scala backend development) because I like it’s productivity and I also like the user centered perspective that I associate with Rails shops. I am reading through lots of startup descriptions (filtered to python, rails, go, and node) and I am wondering if there are any easy signals to search for to find indicators of places that place a strong emphasis on product research. Are there particular tools or methods that I can search for?

Another way to state what I am trying to identify quickly is: not a feature factory, but also some emphasis on velocity.