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Ruby, Rails & SQL Online Test

About the test:

The Ruby, Rails & SQL Online Test uses scenario-based MCQs to evaluate candidates on their proficiency in the Ruby programming language, the Rails web framework, and SQL database. The test assesses candidates' understanding of topics such as model-view-controller architecture, ActiveRecord, database migrations, SQL queries, and database design principles. Candidates are evaluated on their ability to use Ruby and Rails to interact with databases, design database schemas, and write optimized and secure SQL queries for data manipulation and retrieval.

Covered skills:

  • Ruby Basics
  • Rails Fundamentals
  • REST APIs in Rails
  • SQL Joins and Indexes
  • Ruby OOPs
  • Rails MVC
  • SQL CRUD Operations
  • Ruby Coding

9 reasons why
9 reasons why

Adaface Ruby, Rails & SQL Test is the most accurate way to shortlist Ruby Developers



Reason #1

Tests for on-the-job skills

The Ruby, Rails & SQL Online Test helps recruiters and hiring managers identify qualified candidates from a pool of resumes, and helps in taking objective hiring decisions. It reduces the administrative overhead of interviewing too many candidates and saves time by filtering out unqualified candidates at the first step of the hiring process.

The test screens for the following skills that hiring managers look for in candidates:

  • Ability to write clean and efficient Ruby code
  • Understanding of object-oriented programming principles in Ruby
  • Proficiency in Rails framework and its fundamentals
  • Knowledge of Model-View-Controller (MVC) architecture in Rails
  • Experience in developing REST APIs in Rails
  • Familiarity with SQL CRUD operations
  • Understanding of SQL joins and indexes
  • Ability to solve coding problems using Ruby
Reason #2

No trick questions

no trick questions

Traditional assessment tools use trick questions and puzzles for the screening, which creates a lot of frustration among candidates about having to go through irrelevant screening assessments.

View sample questions

The main reason we started Adaface is that traditional pre-employment assessment platforms are not a fair way for companies to evaluate candidates. At Adaface, our mission is to help companies find great candidates by assessing on-the-job skills required for a role.

Why we started Adaface
Reason #3

Non-googleable questions

We have a very high focus on the quality of questions that test for on-the-job skills. Every question is non-googleable and we have a very high bar for the level of subject matter experts we onboard to create these questions. We have crawlers to check if any of the questions are leaked online. If/ when a question gets leaked, we get an alert. We change the question for you & let you know.

How we design questions

These are just a small sample from our library of 10,000+ questions. The actual questions on this Ruby, Rails & SQL Test will be non-googleable.

🧐 Question

Easy

Arrays Strings
Arrays
Strings
Solve
Check the  following Ruby code:
 image
We want the following execution result:
- Commit
- PR
- Merge
What should we replace __BLOCK__  with to achieve this?

Medium

Class and Self
OOPs
Solve
What is the execution result of the following Ruby code?
 image
 image

Easy

Exceptions
Exceptions
OOPs
Solve
What is the result of following Ruby code:
 image

Medium

New Class
OOPs
Singleton
Solve
Check the  following Ruby code:
 image
Which all of the following statements should replace __BLOCK__ to have "Marvel" as execution result?
A: Sample.new.class.ciao
B: Sample.class.new.ciao
C: Sample.new.ciao
D: Sample.ciao

Hard

Movie query problem
Solve
Our intern created the following model scope
 image
and they want to use in this view:
 image
Which of these code snippets they use to fetch the correct results, and avoid the N+1 query issue?
 image

Medium

Multi Select
JOIN
GROUP BY
Solve
Consider the following SQL table:
 image
How many rows does the following SQL query return?
 image

Medium

nth highest sales
Nested queries
User Defined Functions
Solve
Consider the following SQL table:
 image
Which of the following SQL commands will find the ‘nth highest Sales’ if it exists (returns null otherwise)?
 image

Medium

Select & IN
Nested queries
Solve
Consider the following SQL table:
 image
Which of the following SQL queries would return the year when neither a football or cricket winner was chosen?
 image

Medium

Sorting Ubers
Nested queries
Join
Comparison operators
Solve
Consider the following SQL table:
 image
What will be the first two tuples resulting from the following SQL command?
 image

Hard

With, AVG & SUM
MAX() MIN()
Aggregate functions
Solve
Consider the following SQL table:
 image
How many tuples does the following query return?
 image

Easy

Registration Queue
Logic
Queues
Solve
We want to register students for the next semester. All students have a receipt which shows the amount pending for the previous semester. A positive amount (or zero) represents that the student has paid extra fees, and a negative amount represents that they have pending fees to be paid. The students are in a queue for the registration. We want to arrange the students in a way such that the students who have a positive amount on the receipt get registered first as compared to the students who have a negative amount. We are given a queue in the form of an array containing the pending amount.
For example, if the initial queue is [20, 70, -40, 30, -10], then the final queue will be [20, 70, 30, -40, -10]. Note that the sequence of students should not be changed while arranging them unless required to meet the condition.
⚠️⚠️⚠️ Note:
- The first line of the input is the length of the array. The second line contains all the elements of the array.
- The input is already parsed into an array of "strings" and passed to a function. You will need to convert string to integer/number type inside the function.
- You need to "print" the final result (not return it) to pass the test cases.

For the example discussed above, the input will be:
5
20 70 -40 30 -10

Your code needs to print the following to the standard output:
20 70 30 -40 -10

Medium

Visitors Count
Strings
Logic
Solve
A manager hires a staff member to keep a record of the number of men, women, and children visiting the museum daily. The staff will note W if any women visit, M for men, and C for children. You need to write code that takes the string that represents the visits and prints the count of men, woman and children. The sequencing should be in decreasing order. 
Example:

Input:
WWMMWWCCC

Expected Output: 
4W3C2M

Explanation: 
‘W’ has the highest count, then ‘C’, then ‘M’. 
⚠️⚠️⚠️ Note:
- The input is already parsed and passed to a function.
- You need to "print" the final result (not return it) to pass the test cases.
- If the input is- “MMW”, then the expected output is "2M1W" since there is no ‘C’.
- If any of them have the same count, the output should follow this order - M, W, C.
🧐 Question🔧 Skill

Easy

Arrays Strings
Arrays
Strings

2 mins

Ruby
Solve

Medium

Class and Self
OOPs

2 mins

Ruby
Solve

Easy

Exceptions
Exceptions
OOPs

2 mins

Ruby
Solve

Medium

New Class
OOPs
Singleton

2 mins

Ruby
Solve

Hard

Movie query problem

4 mins

Rails
Solve

Medium

Multi Select
JOIN
GROUP BY

2 mins

SQL
Solve

Medium

nth highest sales
Nested queries
User Defined Functions

3 mins

SQL
Solve

Medium

Select & IN
Nested queries

3 mins

SQL
Solve

Medium

Sorting Ubers
Nested queries
Join
Comparison operators

3 mins

SQL
Solve

Hard

With, AVG & SUM
MAX() MIN()
Aggregate functions

2 mins

SQL
Solve

Easy

Registration Queue
Logic
Queues

30 mins

Coding
Solve

Medium

Visitors Count
Strings
Logic

30 mins

Coding
Solve
🧐 Question🔧 Skill💪 Difficulty⌛ Time
Arrays Strings
Arrays
Strings
Ruby
Easy2 mins
Solve
Class and Self
OOPs
Ruby
Medium2 mins
Solve
Exceptions
Exceptions
OOPs
Ruby
Easy2 mins
Solve
New Class
OOPs
Singleton
Ruby
Medium2 mins
Solve
Movie query problem
Rails
Hard4 mins
Solve
Multi Select
JOIN
GROUP BY
SQL
Medium2 mins
Solve
nth highest sales
Nested queries
User Defined Functions
SQL
Medium3 mins
Solve
Select & IN
Nested queries
SQL
Medium3 mins
Solve
Sorting Ubers
Nested queries
Join
Comparison operators
SQL
Medium3 mins
Solve
With, AVG & SUM
MAX() MIN()
Aggregate functions
SQL
Hard2 mins
Solve
Registration Queue
Logic
Queues
Coding
Easy30 minsSolve
Visitors Count
Strings
Logic
Coding
Medium30 minsSolve
Reason #4

1200+ customers in 75 countries

customers in 75 countries
Brandon

With Adaface, we were able to optimise our initial screening process by upwards of 75%, freeing up precious time for both hiring managers and our talent acquisition team alike!


Brandon Lee, Head of People, Love, Bonito

Reason #5

Designed for elimination, not selection

The most important thing while implementing the pre-employment Ruby, Rails & SQL Test in your hiring process is that it is an elimination tool, not a selection tool. In other words: you want to use the test to eliminate the candidates who do poorly on the test, not to select the candidates who come out at the top. While they are super valuable, pre-employment tests do not paint the entire picture of a candidate’s abilities, knowledge, and motivations. Multiple easy questions are more predictive of a candidate's ability than fewer hard questions. Harder questions are often "trick" based questions, which do not provide any meaningful signal about the candidate's skillset.

Science behind Adaface tests
Reason #6

1 click candidate invites

Email invites: You can send candidates an email invite to the Ruby, Rails & SQL Test from your dashboard by entering their email address.

Public link: You can create a public link for each test that you can share with candidates.

API or integrations: You can invite candidates directly from your ATS by using our pre-built integrations with popular ATS systems or building a custom integration with your in-house ATS.

invite candidates
Reason #7

Detailed scorecards & benchmarks

View sample scorecard
Reason #8

High completion rate

Adaface tests are conversational, low-stress, and take just 25-40 mins to complete.

This is why Adaface has the highest test-completion rate (86%), which is more than 2x better than traditional assessments.

test completion rate
Reason #9

Advanced Proctoring


Learn more

About the Ruby, Rails & SQL Assessment Test

Why you should use Pre-employment Ruby, Rails & SQL Online Test?

The Ruby, Rails & SQL Test makes use of scenario-based questions to test for on-the-job skills as opposed to theoretical knowledge, ensuring that candidates who do well on this screening test have the relavant skills. The questions are designed to covered following on-the-job aspects:

  • Ability to write clean and efficient Ruby code
  • Understanding of object-oriented programming concepts in Ruby
  • Experience with building web applications using Ruby on Rails framework
  • Familiarity with the Model-View-Controller (MVC) architecture in Rails
  • Knowledge of designing and implementing REST APIs in Rails
  • Proficiency in performing CRUD operations using SQL
  • Understanding of SQL joins and indexes for efficient database querying
  • Ability to solve complex coding problems using Ruby
  • Experience with version control systems for code management
  • Proficiency in writing testable code and unit test cases

Once the test is sent to a candidate, the candidate receives a link in email to take the test. For each candidate, you will receive a detailed report with skills breakdown and benchmarks to shortlist the top candidates from your pool.

What topics are covered in the Ruby, Rails & SQL Online Test?

  • Ruby Basics

    Ruby Basics refers to the fundamental concepts and syntax of the Ruby programming language. This skill should be measured in the test to assess the candidate's understanding of variables, data types, control structures, and basic programming concepts in Ruby.

  • Ruby OOPs

    Ruby OOPs (Object-Oriented Programming) refers to the ability of a candidate to understand and apply object-oriented principles in Ruby, such as encapsulation, inheritance, and polymorphism. This skill is important to assess as Ruby heavily relies on object-oriented programming concepts and encourages the use of classes and objects.

  • Rails Fundamentals

    Rails Fundamentals assess the candidate's knowledge of the core concepts and features of Ruby on Rails framework. This includes understanding the Model-View-Controller (MVC) architecture, routing, database migrations, and basic CRUD operations in Rails. Evaluating this skill is crucial as Rails is a popular web application framework widely used in industry.

  • Rails MVC

    Rails MVC (Model-View-Controller) refers to the ability to understand and implement the architectural pattern used in Ruby on Rails applications. This includes designing and manipulating models, rendering views, and handling user input through controllers. Assessing this skill helps measure the candidate's understanding of Rails' MVC structure and their ability to develop well-structured and maintainable web applications.

  • REST APIs in Rails

    REST APIs in Rails assess the candidate's knowledge of building, consuming, and testing RESTful APIs using Ruby on Rails. This includes understanding REST principles, designing API endpoints, handling HTTP methods, and implementing authentication and authorization. Measuring this skill is important as APIs play a crucial role in modern application development and integration.

  • SQL CRUD Operations

    SQL CRUD Operations refer to the ability to perform Create, Read, Update, and Delete operations on a database using SQL. This skill should be measured in the test to evaluate the candidate's proficiency in writing SQL queries to manipulate data and interact with databases effectively.

  • SQL Joins and Indexes

    SQL Joins and Indexes assess the candidate's understanding of joining tables and optimizing query performance using indexes in SQL. This includes knowledge of different types of joins (inner join, outer join, etc.) and the usage of indexes to improve query execution time. Evaluating this skill is important as SQL is a widely used language for relational databases, and efficient querying is crucial for ensuring database performance.

  • Ruby Coding

    Ruby Coding refers to the candidate's ability to write clean, efficient, and well-structured Ruby code. This includes following coding conventions, utilizing appropriate data structures and algorithms, and applying best practices in Ruby development. Assessing this skill helps measure the candidate's ability to produce high-quality code and maintainable software solutions.

  • Full list of covered topics

    The actual topics of the questions in the final test will depend on your job description and requirements. However, here's a list of topics you can expect the questions for Ruby, Rails & SQL Test to be based on.

    Ruby syntax
    Variables and data types in Ruby
    Control flow in Ruby
    Functions and methods in Ruby
    Class and object in Ruby
    Inheritance and polymorphism in Ruby
    Rails directory structure
    Routing in Rails
    Models and database in Rails
    Views and templates in Rails
    Controllers and actions in Rails
    Working with RESTful APIs in Rails
    User authentication and authorization in Rails
    Creating and manipulating database tables using SQL
    Selecting and filtering data in SQL
    Updating and deleting data in SQL
    Joining multiple tables in SQL
    Indexing and optimizing SQL queries
    Implementing basic Ruby coding problems
    Using Ruby libraries and gems
    Debugging Ruby code
    Error handling and exception catching in Ruby
    Testing Ruby code using frameworks like RSpec
    Understanding Ruby blocks and iterators
    Working with arrays and hashes in Ruby
    File I/O operations in Ruby
    Understanding Ruby classes and modules
    Implementing associations between Rails models
    Using Git version control in Rails projects
    Deploying Rails applications to production servers
    Working with sessions and cookies in Rails
    Implementing pagination and sorting in Rails
    Query optimization in SQL
    Creating database indexes in Rails
    Deploying RESTful APIs in Rails
    Configuring and using caching in Rails
    Creating and utilizing Rails plugins
    Implementing background jobs in Rails
    Interacting with external APIs in Rails
    Handling database migrations in Rails
    Creating and using partials in Rails views
    Implementing nested resources in Rails
    Building search functionality in Rails
    Implementing file uploads in Rails
    Implementing internationalization in Rails
    Securing Rails applications against common vulnerabilities
    Working with JSON data in Rails
    Optimizing Ruby code for performance
    Creating and using helper methods in Rails views
    Using environment variables in Rails applications
    Implementing API versioning in Rails
    Handling concurrency and thread safety in Ruby
    Working with ActiveRecord associations in Rails
    Implementing data validations in Rails models
    Creating and consuming web services in Rails
    Optimizing SQL queries using indexes
    Implementing full-text search in SQL
    Understanding database normalization in SQL
    Implementing transaction management in Rails
    Working with time and dates in Ruby

What roles can I use the Ruby, Rails & SQL Online Test for?

  • Ruby Developer
  • Rails Developer
  • RoR Developer

How is the Ruby, Rails & SQL Online Test customized for senior candidates?

For intermediate/ experienced candidates, we customize the assessment questions to include advanced topics and increase the difficulty level of the questions. This might include adding questions on topics like

  • Understanding of software development best practices and coding standards
  • Knowledge of web security principles and common vulnerabilities
  • Ability to optimize and improve application performance
  • Experience with deploying and managing applications on cloud platforms
  • Knowledge of asynchronous programming and background job processing
  • Understanding of caching mechanisms for improving application speed
  • Experience with integrating third-party libraries and APIs
  • Familiarity with front-end technologies like HTML, CSS, and JavaScript
  • Ability to collaborate effectively with cross-functional teams
  • Strong problem-solving and analytical skills
  • Excellent communication and documentation skills

The coding question for experienced candidates will be of a higher difficulty level to evaluate more hands-on experience.

Singapore government logo

The hiring managers felt that through the technical questions that they asked during the panel interviews, they were able to tell which candidates had better scores, and differentiated with those who did not score as well. They are highly satisfied with the quality of candidates shortlisted with the Adaface screening.


85%
reduction in screening time

Ruby, Rails & SQL Hiring Test FAQs

Can I combine multiple skills into one custom assessment?

Yes, absolutely. Custom assessments are set up based on your job description, and will include questions on all must-have skills you specify. Here's a quick guide on how you can request a custom test.

Do you have any anti-cheating or proctoring features in place?

We have the following anti-cheating features in place:

  • Non-googleable questions
  • IP proctoring
  • Screen proctoring
  • Web proctoring
  • Webcam proctoring
  • Plagiarism detection
  • Secure browser
  • Copy paste protection

Read more about the proctoring features.

How do I interpret test scores?

The primary thing to keep in mind is that an assessment is an elimination tool, not a selection tool. A skills assessment is optimized to help you eliminate candidates who are not technically qualified for the role, it is not optimized to help you find the best candidate for the role. So the ideal way to use an assessment is to decide a threshold score (typically 55%, we help you benchmark) and invite all candidates who score above the threshold for the next rounds of interview.

What experience level can I use this test for?

Each Adaface assessment is customized to your job description/ ideal candidate persona (our subject matter experts will pick the right questions for your assessment from our library of 10000+ questions). This assessment can be customized for any experience level.

Does every candidate get the same questions?

Yes, it makes it much easier for you to compare candidates. Options for MCQ questions and the order of questions are randomized. We have anti-cheating/ proctoring features in place. In our enterprise plan, we also have the option to create multiple versions of the same assessment with questions of similar difficulty levels.

I'm a candidate. Can I try a practice test?

No. Unfortunately, we do not support practice tests at the moment. However, you can use our sample questions for practice.

What is the cost of using this test?

You can check out our pricing plans.

Can I get a free trial?

Yes, you can sign up for free and preview this test.

I just moved to a paid plan. How can I request a custom assessment?

Here is a quick guide on how to request a custom assessment on Adaface.

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