Ruby libraries

Rails is a full-stack web framework covering routing, ORM, migrations, background jobs, mailers, caching and testing, built on convention over configuration.

RSpec is Ruby's behaviour-driven testing framework, with nested example groups, expressive matchers and built-in test doubles.

Sidekiq is a high-performance background job processor for Ruby, using threads and Redis to run many jobs per process.

RuboCop is a Ruby static code analyser and formatter, enforcing the community style guide with hundreds of configurable cops and autocorrection.

Sinatra is a minimal Ruby web framework — routes are blocks, there is no imposed structure, and the whole application can be one file.

Puma is a concurrent HTTP server for Ruby, using a thread pool and optional worker processes, and is the default server for Rails.

Devise is a flexible authentication solution for Rails built on Warden, providing registration, sessions, password recovery, confirmation and lockout as composable modules.

FactoryBot builds test objects from declarative factories, replacing static fixtures with composable, overridable definitions.

Pundit provides object-oriented authorisation for Rails using plain Ruby policy classes, one per model.

Kaminari is a pagination library for Rails and ActiveRecord, with scope-based paging, customisable views and support for non-ActiveRecord collections.