The ultimate guide to Ruby concurrency interviews. Developed by FAANG engineers, this course covers Monitors, Deferred Callbacks and problem-solving strategies for Reader-Writer and Dining Philosopher Problems.

Concurrency in Ruby is one of the most complex and advanced topics brought up during senior engineering interviews. Knowledge of concurrency and multithreading can put interviewees at a considerable advantage. This course lays the foundations of advanced concurrency and multithreading and explains concepts such as Monitors and Deferred Callbacks in depth. It also builds simple and complete solutions to popular concurrency problems that can be asked about in interviews like the Reader-Writer Problem and the Dining Philosopher Problem. While prior knowledge of concurrency is not required to follow through with this course, familiarity with the basics of Ruby would be helpful.

Ruby Concurrency for Senior Engineering Interviews

<div class="ans">
# Ping Pong Program

<p>We'll write a program that will print ping and pong in strict alternation on the console. Our program will consist of two threads, one to write each string. The challenge is to coordinate the two threads to take turns one after another when printing to the console.</p>

<p>We'll use a boolean <code class="mthd">flag</code> variable to remember which thread should go next. While one thread prints on the console, we'll need a way to stop the other thread from moving forward. One and an inefficient way is to busy-wait in a while loop and constantly poll for a change in the while loop's condition. For now, we'll stick to this strategy and improve upon it in later lessons.</p>

<p>The code appears in the code widget below: </p>

</div>

<div>
# Ping Pong Program

<p>We'll write a program that will print ping and pong in strict alternation on the console. Our program will consist of two threads, one to write each string. The challenge is to coordinate the two threads to take turns one after another when printing to the console.</p>

<p>We'll use a boolean <code>flag</code> variable to remember which thread should go next. While one thread prints on the console, we'll need a way to stop the other thread from moving forward. One and an inefficient way is to busy-wait in a while loop and constantly poll for a change in the while loop's condition. For now, we'll stick to this strategy and improve upon it in later lessons.</p>

<p>The code appears in the code widget below: </p>

</div>

This lesson continues the discussion on instantiating threads.

The Basics

API Overview

Brief Intro to Asynchronous Programming

Interview Practice Problems

Bonus Questions

Epilogue

... continued

Ping Pong Program