For validations, at least, there are Rails plugins for checking model validations in the browser (by augmenting the form helpers to generate Javascript which do

For validations, at least, there are Rails plugins for checking model validations in the browser (by augmenting the form helpers to generate Javascript which does the checks). For example, https://github.com/dnclabs/client_side_validations https://github.com/dnclabs/client_side_validations This won't work to forward more complicated logic, though. For those who are really feeling the pain, the best cure might be writing the back end using server-side JS, so you can run that code in either environment.