Ruby on Rails Technology & Digital Applications 4

Question 1

Which Rails command generates a fully resourceful JSON API controller with no views?

Accepted Answer

rails generate scaffold Resource --api

Answer

`rails generate scaffold Resource --api` creates model, migration, routes, and a controller rendering JSON without view templates.

Question 2

In Rails, which cache store is best suited for a multi-server production deployment?

Accepted Answer

ActiveSupport::Cache::RedisCacheStore or MemCacheStore

Answer

Redis and Memcached cache stores are shared across servers, making them suitable for horizontally scaled production deployments.

Question 3

What does enabling `config.force_ssl = true` do in a Rails production environment?

Accepted Answer

Redirects all HTTP requests to HTTPS and sets HSTS headers

Answer

`force_ssl` adds the `ActionDispatch::SSL` middleware that redirects HTTP→HTTPS and adds Strict-Transport-Security headers.

Question 4

Which Sidekiq feature allows failed background jobs to be automatically retried with exponential backoff?

Accepted Answer

Built-in retry logic; jobs are retried up to 25 times by default with exponential delays

Answer

Sidekiq automatically retries failed jobs up to 25 times using exponential backoff, configurable per worker via `sidekiq_options`.

Question 5

When uploading files to S3 from a Rails app using Active Storage, what advantage does direct upload provide?

Accepted Answer

Files go directly from the browser to S3, bypassing the Rails server

Answer

Direct upload lets the browser send large files straight to S3 using pre-signed URLs, reducing load on the Rails server.

Ruby on Rails Practice Test