Ryan ryanhburbank

Originally published in June 2008

When hiring Ruby on Rails programmers, knowing the right questions to ask during an interview was a real challenge for me at first. In 30 minutes or less, it's difficult to get a solid read on a candidate's skill set without looking at code they've previously written. And in the corporate/enterprise world, I often don't have access to their previous work.

To ensure we hired competent ruby developers at my last job, I created a list of 15 ruby questions -- a ruby measuring stick if you will -- to select the cream of the crop that walked through our doors.

What to expect

Candidates will typically give you a range of responses based on their experience and personality. So it's up to you to decide the correctness of their answer.

Studying for a Tech Interview Sucks, so Here's a Cheat Sheet to Help

This list is meant to be a both a quick guide and reference for further research into these topics. It's basically a summary of that comp sci course you never took or forgot about, so there's no way it can cover everything in depth. It also will be available as a gist on Github for everyone to edit and add to.

Data Structure Basics

###Array ####Definition:

Stores data elements based on an sequential, most commonly 0 based, index.
Based on tuples from set theory.

Web Security

This post outlines three common web security vulnerabilities with specific examples in Rails. For a more complete list, I highly recommend the OWASP Rails security cheatsheet.

Cross-Site Scripting (XSS)

A cross-site scripting attack is when malicious scripts are injected into a web site in order to compromise it.

For example, let's say we want to allow html tags such as <strong> in our blog comments, so we render raw output using the Rails method #html_safe:

Instructions:

Download this application skeleton.
Convert the app to use AJAX.
Add any files you changed to your gist and submit your code.

	<!DOCTYPE html>
	<html>
	<head>
	<title>Assignment 2</title>
	<meta charset="UTF-8">
	/*Code for button CSS
	.button {
	background-color="#00FFCC"
	color="#CCAABB"
	}

	<!DOCTYPE html>
	<html lang="en">
	<head>

	<style>
	.link, .link a, .signupframe{
	color: #226699;
	font-family: Arial, Helvetica, sans-serif;
	font-size: 13px;
	}

	//------------------------------------------------------------------------------------------------------------------
	// YOUR CODE: Create your Zoo "object literal" and Animal "constructor" and "prototypes" here.
	//------------------------------------------------------------------------------------------------------------------
	function Animal(name, numOfLegs) {
	this.name = name;
	this.numOfLegs = numOfLegs;
	};

	Animal.prototype.identify = function(){

	<!doctype html>
	<html>

	<head>
	<link rel="stylesheet" href="http://cdn.jsdelivr.net/normalize/2.1.0/normalize.css">
	<link rel="stylesheet" href="main.css">
	<link rel="stylesheet" href="http://fonts.googleapis.com/css?family=Open+Sans:300,400,600,700,800">
	<link rel="stylesheet" href="http://fonts.googleapis.com/css?family=Lato:100,900">
	<link rel="stylesheet" href="http://cdnjs.cloudflare.com/ajax/libs/font-awesome/3.0.2/css/font-awesome.min.css">
	</head>

	require 'net/http'
	require 'nokogiri'
	require 'uri'

	require_relative 'util'

	class Browser
	def run!
	get_url

	class Vehicle
	attr_reader :color, :wheels, :status
	def initialize(args)
	@color = args[:color]
	@wheels = 4
	@status = :stopped
	end

	def drive
	@status = :driving