I still think Rails has the best ORM design I've ever seen, iterated with practical applications. Django's ORM and migrations are, for lack of a better word, odd.
I'm a bit surprised that people here argue that no one using Rails would ever want to interface with other languages. Most big companies do. How can you not interface with python these days.
Looks to me like celery might just be the only job queue left like that. Might be worth writing a current ruby en-queuing library for it. Retracting my previous statement about ActiveJob since it would probably be too much effort to execute anything bidirectionally.
We started another project later on and we planned the database first. We wrote one model per table, no inheritance, only a few cleanly delimited apps. We still use makemigrations and migrate but if we want we can write a piece of software on any language to access that database.
By the way, celery was born as a protocol spec to support multiple languages but never moved past Python. I can't google a quote for that, I remember I saw it years ago in the documentation somewhere.