Top 76 Ruby on Rails Interview Questions & Answers (2026)

01 What is Ruby on Rails? 02 What is the MVC pattern in Rails? 03 What is Convention over Configuration in Rails? 04 What is ActiveRecord in Rails? 05 What is a Rails migration? 06 What are Rails routes? 07 What are the 7 RESTful actions in Rails? 08 What is a Rails generator? 09 What is a Gemfile and Bundler in Rails? 10 What is the Rails directory structure? 11 What are ActiveRecord associations? 12 What are ActiveRecord validations? 13 What are ActiveRecord callbacks? 14 What is the difference between render and redirect_to in Rails? 15 What is strong parameters in Rails? 16 What is ERB in Rails? 17 What is the difference between GET and POST in Rails forms? 18 What is CSRF protection in Rails? 19 What are Rails helpers? 20 What are Rails scopes? 21 What is flash in Rails? 22 What is session in Rails? 23 What is the asset pipeline in Rails? 24 What is database seeding in Rails? 25 What are environment files in Rails? 26 What is an ActiveRecord query interface? 27 What is the difference between find and find_by in Rails? 28 What are partials in Rails views? 29 What is concerns in Rails? 30 What is has_secure_password in Rails? 31 What are Rails environments and how do you check the current one? 32 What is Rails console? 33 What is the difference between belongs_to and has_one? 34 What is ActiveRecord::Base vs ApplicationRecord? 35 What is eager loading vs lazy loading in Rails? 36 What are named routes in Rails? 37 What is the difference between update and update_attribute? 38 What is Rails scaffolding? 39 What are Rails layouts? 40 What is the Rails request-response lifecycle? 41 What is polymorphic association in Rails?

01 What is the N+1 query problem and how do you fix it? 02 What is caching in Rails and what types are available? 03 What is a service object in Rails? 04 What is a background job in Rails and how is it implemented? 05 What is ActionMailer in Rails? 06 What is Devise in Rails? 07 What is Pundit or CanCanCan in Rails? 08 What is Rails API mode? 09 What are transactions in ActiveRecord? 10 What is counter_cache in Rails? 11 What is the difference between dependent: :destroy and dependent: :delete_all? 12 What is Single Table Inheritance (STI) in Rails? 13 What is ActionCable in Rails? 14 What is ActiveStorage in Rails? 15 What is Hotwire and Turbo in modern Rails? 16 What is the difference between update_all and update in Rails? 17 What is Rails testing (RSpec vs Minitest)? 18 What is database indexing and why is it important in Rails? 19 What is the Rails router's namespace and scope? 20 What is an API versioning strategy in Rails? 21 What are Rails concerns and when should you use them? 22 What is ActiveRecord dirty tracking?

01 What is metaprogramming in Ruby/Rails and give examples? 02 What is the difference between include, extend, and prepend in Ruby? 03 How does Rails handle database connection pooling? 04 What is Rack and how does Rails relate to it? 05 What is query optimization with explain in Rails? 06 What are Rails engines and how are they used? 07 What is the difference between class methods and instance methods in ActiveRecord? 08 What is optimistic vs pessimistic locking in Rails? 09 What is ActiveRecord's STI vs polymorphic associations — when to use each? 10 How do you handle background job failures and retries in Rails? 11 What is database sharding in the context of Rails? 12 What is the Observer pattern in Rails and is it still used? 13 What is the role of Puma in Rails deployment?