Backend: Ruby, Ruby on Rails, ActiveRecord
Databases: PostgreSQL, MySQL
Background Jobs: Sidekiq, Resque
Caching: Redis, Memcached
Testing: RSpec, Minitest, Capybara
Code Quality: RuboCop, StandardRB
Cloud: AWS, GCP, Heroku
Monitoring: New Relic, Datadog, Honeybadger, Rollbar
Version Control: Git, GitHub