Brainstem allows you to create rich API presenters that know how to filter, sort, and include associations.

Cucumber Factory allows you to create ActiveRecord models from your Cucumber features without writing step definitions for each model.

Delayed is a multi-threaded, SQL-driven ActiveJob backend used at Betterment to process millions of background jobs per day. It supports postgres, mysql, and sqlite, and is designed to be Reliable (with co-transactional job enqueues and guaranteed, at-least-once execution), Scalable (with an optimized pickup query and concurrent job execution), Resilient (with built-in retry mechanisms, exponential backoff, and failed job preservation), and Maintainable (with robust instrumentation, continuous monitoring, and priority-based alerting).

A modern profiler for your Rails application

Easy role authorization in rails

Instruments for Factory Bot

Preload factories (Factory Bot) just like fixtures. It will be easier and, probably, faster!

Preseed reusable data for factory girl

Adds query origin tracing to your logs.

https://github.com/tsukasaoishi/fresh_connection

Another business actions architecture for Rails apps

Jazz theory is a mathematical system of concepts and relationships, why not make an ActiveModel representation of those concepts?

Double entry bookkeeping with Rails

Let ActiveRecord serialize and cast your UUIDs to and from binary columns in your database.

Store nested hashes and other types in ActiveRecord hstores

Off The Rails ActiveRecord: Use ActiveRecord with Grape, Sinatra, Rack, or anything else! Formerly known as 'grape-activerecord'.

An extension to paper_trail, using this you can fetch actual object who was responsible for this change

Adds the validates_uniqueness_without_deleted validator to ignore deleted fields when validating for uniqueness.

Organize ActiveRecord model into a tree structure using PostgreSQL LTree

pluto-models - planet schema 'n' models for easy (re)use