• Origin story: Randy Schmidt, the managing director of the Burns & McDonnell Terminals and Pipelines group, introduced the term “fullstack development” on June 03, 2008. He described a fullstack developer as someone that does design, markup, styling, behavior, and programming.
• Widely popular: As of 2019, according to Evans Data Corporation, there are about 26 million software developers in the world. The USA has the highest number of software developers, approximately 4,2 million.
• Width of knowledge: A fullstack developer is a programmer with knowledge across all layers of an application.
  1. Presentation Layer: The front-end of an application built using programming languages like HTML, CSS, JavaScript, jQuery, and various JavaScript libraries such as Foundation, AngularJS, Backbone, Ember.js, and React JS.
  2. Logic Layer: The backend of an application built using programming languages like Java, PHP, .Net, Ruby, and Python.
  3. Data Layer: A sub-group of the logic layer that deals with how data is created, modified, read, managed, and deleted using databases like SQL Server, MySQL, Oracle, and PostgreSQL.

• Fullstack developers can solve many problems: Companies hire based on what issues the candidates can solve for the company. Fullstack developers can work on both backend, frontend, and the protocols that connect the two. Being able to create a software product end to end independently gives them an added advantage as compared to other developers.
• Role flexibility: Fullstack developers with the knowledge to work on different projects provide managerial flexibility to move people between teams as businesses always need change.

Fullstack developers make use of a broad range of tools. Some of these are as follows:

1. Fullstack development IDE - VSCode

Visual Studio Code or VSCode has been rated as one of the best JavaScript IDEs available for development. It has in-built support for JS languages as well as extensions for other programming languages like Python, PHP, and C#.

2. API Testing - Postman

Postman is a reliable API testing tool that makes of easy-to-use configuration. It is particularly great for REST API testing.

3. CI/CD - Jenkins

This is an open-source automation software tool. Fullstack developers as well as others alike use this tool for building, testing, and deploying their apps. Getting familiar with the Jenkins pipeline is quite crucial for fullstack developers.

4. Version Control - GitBash

GitBash allows for easy source control management. The tool uses versioning and commit history to make the code management process simpler.

Below are some key points that we at Flexiple have learned through trial and error - a process of filtering through over 15,000 developers. You can use these in your process to hire fullstack developers.

• Years of software development experience: Be specific about the technology you’re looking for and the number of years of experience needed. A proxy to years of experience can be the number of production-level apps worked on.
• Expertise in a specific language: All languages have their peculiarities and nuances. While good Fullstack developers can pick up other languages, it’s a plus point to hire a developer who already has expertise in it.
• Type of products built in the past: Based on the type of product you are trying to build - social network, SAAS product, etc. - you can prioritize certain developers over others.
• Exposure to specific industries: Developers who have built products in certain industries will already know key aspects of laying the foundation for a great product and will be able to predict possible problems.
• Experience working remotely: A developer with past remote work experience is an added advantage as they would have first-hand experience of everything - right from how contracts work to streamlined communication, as well as timelines and deliverables.
• Strong communication: An essential thing to look at when hiring a freelancer is excellent communication skills. Since all the interaction happens online, a freelancer should be able to effectively communicate to ensure a streamlined execution of all work.

Now that you have made a quality JD, it can still be tricky to evaluate the skills of your applicants when you hire fullstack developers. To help you with that, we have created a pool of questions that a good fullstack developer should be comfortable with.

It is important to note that the ability to answer these questions doesn't imply that you have a top quality candidate. But it definitely is a big step in that direction.

To help you navigate through these questions, we’ve categorized the interview questions in 3 parts:

A. Basic concepts: Includes all basic concepts used across languages. This section will give you an understanding of how strong their programming foundation is.

B. Advanced concepts: Includes all concepts that someone with higher expertise should know.

C. DS/Algorithm questions: To test the logical capability of the candidate.

A. Basic concepts

1. Explain Observables in Angular

Observables are used to pass messages between various parts of your Angular application. Observables are declarative and are used to deliver multiple values of any type.

Observables are commonly used in asynchronous programming and to handle multiple values.

2. List a few advantages of using MySQL?

A few noteworthy advantages of using MySQL are

1. High Performance - MySQL was built with a lot of focus on power/ performance
2. Flexibility - MySQL can be used on all operating systems
3. Security - Good security and storage management system
4. Query Caching - Increases the speed of MySQL drastically
5. Replication - MySQL servers can be very easily replicated

B. Advanced concepts

1. Why is spring-boot-maven-plugin used?

This Maven plugin provides Spring Boot support to Apache Maven. This allows users to create and package an executable jar or war archives. It also allows you to start your application before running integration tests.

To add the plugin to your project, add this XML code in the plugin section in your pom.xml as shown below.

The following code can be used to configure a MySQL database and is the answer to the aforementioned Spring Boot interview question:

<project>
    <modelVersion>4.0.0</modelVersion>
    <artifactId>getting-started</artifactId>
    <!-- ... -->
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

2. What are cache-control headers?

Cache-control headers help attain caching ability and are also used to control caching.

The most commonly used cache-control headers are:

• Public - Resources marked as public can be cached by any component between the client and the server.
• Private - These resources are marked private and can only be cached by the client.
• No-Store - In this third type, browsers aren’t allowed to cache a response and the data must be always pulled from the client. This type of cache control is used for sensitive data like bank details or passwords.

C. Data Structure/ Algorithm

1. Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid. An input string is valid if: Open brackets must be closed by the same type of brackets. Open brackets must be closed in the correct order. Note that an empty string is also considered valid.

class ValidParenthesesFunc {
    func isValid(_ s: String) -> Bool {
        var stk = [Character]()

        for char in s {
            if char == "(" || char == "[" || char == "{" {
                stk .append(char)
            } else if char == ")" {
                guard stk.count != 0 && stk.removeLast() == "(" else {
                    return false
                }
            } else if char == "]" {
                guard stk.count != 0 && stk.removeLast() == "[" else {
                    return false
                }
            } else if char == "}" {
                guard stk.count != 0 && stk.removeLast() == "{" else {
                    return false
                }
            }
        }
        return stk.isEmpty
    }
}

The above code will input 0(false). 

2.  Write a program to find whether a string or number is palindrome or not.

function palindrome(myString){
    var removeChar = myString.replace(/[^A-Z0-9]/ig, "").toLowerCase();
    var checkPalindrome = removeChar.split('').reverse().join('');
        if(removeChar === checkPalindrome){
          document.write("<div>"+ myString + " is a Palindrome<div>");
        }else{
          document.write("<div>" + myString + " is not a Palindrome <div>");
        }
}
palindrome('"Madam"')
palindrome('"Star Wars"')
palindrome('"7,10,7,8,9"')

The output of the above code will be: 

"Madam" is a Palindrome
"Star Wars" is not a Palindrome.
"7,10,7,8,9" is not a Palindrome.

3. What will the output of the following code be?

var x = 10;
var y = 5;
var z = 3;
if (x / y / z)
     document.write("hi");
else
    document.write("hello");

The answer is A, the floating-point division in JS returns a non zero value = 0.66 which evaluates to 
true and outputs ‘hi’.

That is everything you need to know about hiring a freelance Fullstack developer. As discussed, it isn't easy to find a quality freelance Fullstack developer but this guide makes the process easier for you. To offload the entire hiring process, reach out to us at Flexiple. We've designed a high-quality, 6-step screening process to find the top 1%, freelance developers. You can find the best freelance Fullstack developers here. We've already served over a hundred clients, earning great reviews for the quality of service.

Lastly, to quickly summarize it for you:

• Note your project requirements and hire accordingly. Do not go for the lowest or the highest-paid developer.
• Don’t hire without vetting- consider asking questions right from the basics to advanced to logical questions.
• Look for companies like Flexiple that help you find the perfect fit.

That's a wrap on all the info you need to hire fullstack developers. Happy hiring! :)