Ruby on Rails Professional Standards & Competencies 3

Question 1

What Rails testing competency is considered a professional baseline for any production Rails application?

Accepted Answer

Maintaining a test suite with model, controller/request, and integration tests that runs on CI

Answer

A professional Rails application maintains a balanced test pyramid with unit, integration, and system tests running automatically in a CI/CD pipeline.

Question 2

When should a Rails developer use `config/credentials.yml.enc` instead of environment variables?

Accepted Answer

For secrets that need to be version-controlled securely and shared across the team via the master key

Answer

Rails encrypted credentials let teams version-control secrets safely, sharing them via a separate master key rather than passing raw secrets out-of-band.

Question 3

A junior developer on your Rails team frequently pushes directly to main. What professional practice should the team adopt?

Accepted Answer

Enforce branch protection rules and require pull request reviews before merging

Answer

Branch protection rules with required reviews are the industry-standard Git workflow practice to ensure code quality and prevent accidental breakage on main.

Question 4

Which principle guides a Rails developer to use `has_many :through` instead of `has_and_belongs_to_many`?

Accepted Answer

has_many :through allows adding attributes to the join model, following the principle of preferring explicit, extensible data models

Answer

has_many :through is preferred professionally because the named join model can hold additional attributes and validations, making the data model more explicit and extensible.

Question 5

What does 'N+1 query awareness' indicate about a Rails developer's professional competency?

Accepted Answer

They understand ActiveRecord lazy loading and proactively use eager loading (includes/preload) to avoid cascading DB queries

Answer

Recognizing and resolving N+1 queries by using eager loading is a fundamental Rails performance competency that distinguishes experienced developers.

Ruby on Rails Practice Test

Ruby on Rails Practice Test

Ruby on Rails Professional Standards & Competencies 3