I'm not "married" with the idea of working there, as a matter of fact I'm already on the interview process with another company (remote too).
But going back to your question, this is a hard one... Unfortunately, I guess most companies look for experience in a specific framework, not even in a language in senior roles. Probably you would have to find some company and consider pay cut/start yours with the new stack. I think smaller companies may be less picky about your stack. You could also look for team lead roles and practice new stack while leading a team. Sometimes companies let you introduce a new stack, but it has to have a good reason. If you work with django I see no reason for rails.
https://about.gitlab.com/handbook/people-operations/global-c...
It's a bummer TBH, I'd need to take a big pay cut to work there.
Thanks for the information.