Ruby on Rails is becoming a widely used technology in web development - and like other IT professionals, Ruby developers are increasingly often hired offshore. That is a great opportunity for a business to cut down expenses, but the hiring becomes more challenging.
Finding the right developers in a pile of CVs is always difficult, and when you hire an offshore Ruby on Rails developer, you get additional challenges, like the language and cultural barriers, the specifics of their education system and the way development process is organized in their country, and so on. That’s why the right Ruby on Rails interview questions matter even more for offshore staffing than they do for an onshore hiring campaign.
The main goal of your offshore Ruby on Rails developer interview should be to identify the programmer who has both theoretical knowledge of the language and the framework and a deep understanding of and practical experience with them.
Start the interview with a sort of Ruby on Rails test to check your candidate’s level of knowledge. These Ruby on Rails interview questions can be grouped like this:
Ruby Interview Questions
- How do you define class, instance, and global variables?
- What is rubygems?
- What is a module?
- What is a Range?
- What is a Symbol?
- How are a Symbol and a String different?
- How do “and” and “&&” operators differ?
- How do you define a custom Exception?
Rails Interview Questions
- What is Scope in Rails?
- What is a sweeper?
- What is an observer?
- What is a filter and when is it called?
- How do you implement caching in Rails?
- How do you create a REST API for your app?
- What is a polymorphic association and how do you implement it?
- What is fields_for used for?
A good idea is also to test the Ruby developer on their knowledge of test frameworks and plugins, as Ruby on Rails has a number of test frameworks, both built-in and third-party, and the community offers plenty of plugins for use. These questions may include:
- What is the difference between functional testing and unit testing?
- Do you have experience using a mocking framework?
- Do you have any experience with BDD using RSpec or Cucumber?
- What plugin would you suggest for full-text search?
- What is your most used plugin for user authorization?
- How do you create a plugin?
After that, you can proceed to more in-depth questions that will help you see if the candidate has a bigger picture of the technology and how thoughtfully they apply it in development.
These are the questions that create a discussion and encourage your potential Ruby developer to express their opinion. Good examples are:
- Twitter is developed using Ruby on Rails. Do you think it was a wise decision and why/why not?
- Ruby has a pretty unique approach to the multiple inheritance problem. Can you explain this approach and its strong/weak points?
- Why use Ruby with its messy Perl lineage, not Python, for example?
These lists of questions are far from complete, but, hopefully, they will be helpful in your process of finding the right offshore Ruby on Rails developer.