Senior Ruby on Rails Developer Interview Questions and Answers

An application running in cloud with tightly coupled infrastructure can be deployed to on-premise by decoupling the components and using containerization.

• Decouple the application components to make them more portable

• Use containerization technologies like Docker to package the application and its dependencies

• Deploy the containerized application to on-premise servers using tools like Kubernetes for orchestration

Use a tool like Rails migration to add a new column to the database table in production with 100 million data.

• Create a new Rails migration file to add the new column to the database table.

• Test the migration locally to ensure it works as expected.

• Deploy the migration to the production environment during a maintenance window to avoid downtime.

• Consider using tools like ActiveRecord's `change_column` method to efficiently add the new column to a large dataset.

STI is used for inheritance while polymorphic association is used for multiple associations

• STI is used for modeling inheritance relationships where different classes share common attributes and behaviors

• Polymorphic association is used when a model can belong to more than one other model on a single association

• STI can lead to a large number of columns in a table, while polymorphic association requires an additional column to store the association type and ID

• STI can be more eff...read more

CSRF tokens and CSP headers are important security measures to protect against cross-site scripting attacks.

• CSRF tokens are used to prevent cross-site request forgery attacks by generating a unique token for each user session.

• CSP headers help prevent cross-site scripting attacks by specifying which resources can be loaded on a webpage.

• Both CSRF tokens and CSP headers are essential in securing web applications against malicious attacks.

Implementing an API rate limiter to control the number of requests a user can make within a certain time frame.

• Use a token bucket algorithm to track and limit the number of requests per user.

• Set a limit on the number of requests allowed per user within a specific time window.

• Implement a sliding window approach to track request timestamps and enforce rate limits.

• Consider using Redis or a similar caching mechanism to store and manage request data efficiently.