Ruby Developer interview questions

Ruby is a dynamic, open-source programming language with a focus on simplicity and productivity. It is commonly used for web development due to its elegant syntax and the robust framework Ruby on Rails, which accelerates web application development.

Ruby on Rails, or Rails, is a web application framework written in Ruby. It provides default structures for databases, web services, and web pages. Key advantages include convention over configuration, an active community, ease of use, and a strong focus on testability.

In Ruby, a symbol is a lightweight, immutable string used mainly as identifiers, whereas a string is a mutable sequence of characters. Symbols are often used to represent keys in hashes or for identifiers in method calls.

Mixin is a module that you include into a class to extend its functionality. In Ruby, Mixins allow the inclusion of modules within classes, providing a mechanism to share methods across classes without using inheritance.

Gems in Ruby are packages or libraries that add functionality to Ruby programs. They can include code, documentation, and even a task automation system. Gems help developers reuse code and share functionalities across projects.

Garbage collection in Ruby is a process that automatically frees up memory used by objects that are no longer accessible or needed, thus preventing memory leaks. Ruby uses a mark-and-sweep garbage collector to automatically clean up unused objects.

Blocks are anonymous functions that can be passed to methods in Ruby. They are used to encapsulate chunks of code and can be invoked at a later time, allowing for powerful iterations and code abstraction.

Some common Ruby design patterns include Singleton, Observer, Decorator, and Factory patterns. These patterns solve specific design problems and help in writing more efficient and maintainable code.

Database migrations in Ruby on Rails are a convenient way to alter the database schema over time. They allow developers to version control their database structure, facilitating schema changes without manual SQL efforts.

Ensuring code quality involves using practices like writing tests (RSpec), code reviews, and applying SOLID principles. Performance optimization can be achieved with profiling tools, optimizing database queries, and employing caching mechanisms.