Ask HN: How should I dive back into Rails after a long haitus?

Background: I've always worked in operations. I dug into RoR years ago, when it was the exciting new technology. I learned Ruby, worked through the rails tutorials, and made a few projects using Rails at that time (mostly for personal and internal use). I learned enough javascript to get by as well.

None of this was ever my core job responsibility. After a while I moved back to Python. I did a few things with Django, before basically being pushed into a pure operations role.

Over the last five years, my career has stagnated. I still do some python scripting for operations-y tasks, but I'm woefully outdated when it comes to the modern web.

My employer has an opening for a rails developer. I know my resume is thin on this front, but I think I have a shot because I'm an internal candidate who is generally well respected based on my other work in the organization. I might be able to convince them to take a chance on me in this role.

Based on reading HN, Rails seems like a bit of a dinosaur now, but then again, so am I, so perhaps we're made for each other? So if you're me, and you want to ramp back up fast (like, in time for a job interview...) what do you do next? What is it that I need to know, right away?