In firebase is there backend logic or is it all supposed to take place client side? I glanced over it yesterday but I am going with DynamoDB + Sails.js on heroku currently as it seems like the quickest platform to build a backend API for my app MVP.

I have experience in JavaScript and the app is react native but server side code is newer to me so if HN has any wisdom I am looking for development speed foremost with maintainability and performance as a lesser priority.