How to hire expert backend developers – the right way

How to hire expert backend developers
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In the business world, you will always come across new challenges and new ways to grow.

After the isolation we all endured during the COVID-19 crisis, many companies realized the key to success lies in implementing digital transformation and a platform-based business model. The choice is yours – go digital, or go home![1] 

Since many companies are looking for ways to digitize their products, backend developers are in high demand. A tree is strong because of its roots – similarly, if you want to create a good application, you need to build it on a solid foundation. 

That is what backend developers take care of. Backend development builds the business logic of a system, which is, to put it simply, the heart of your application. 

Hiring a highly-qualified backend developer who can write clean code is crucial for ensuring the efficiency of your product and the positive user experience of your clients. 

Recruiting for every position has its challenges but hiring a backend developer can be particularly taxing. One of the main reasons for that is the huge shortage of developers worldwide.

According to US Labor Statistics, as of December 2020, the shortage amounts to 40 million workers and is expected to reach 85.2 million by 2030.[2] 

Why is this happening?

Forbes explains that part of the reason for the shortage of skilled developers lies in the way most companies go about hiring. Making a snap judgment based on someone’s resume or a single interview simply isn’t enough for unbiased recruiting. 

Skill assessments help you develop a fair, streamlined, and data-driven hiring process which is the backbone of any successful business. 

Skills tests objectively measure an applicant’s capabilities and enable you to become familiar with their strengths and weaknesses. They eliminate the need for resumes and help you make your recruitment process much easier and more efficient.

What does a backend developer do?

While frontend developers work on the user interface, backend developers are the power behind the scenes. End users don’t interact with their code, but websites and applications won’t work without it. 

To get a better understanding of what a backend developer does, let’s imagine you want to order something on eBay and you input your personal information on the form. As if by magic, this places your order. How does this happen? Where does the data go?

The place where your information goes to be processed is called the backend. Backend developers do server-side programming and are responsible for those parts of an application or website that remain hidden from the public eye but actually power it. 

They create and maintain the core foundation and functionality of your digitized product, manage the database and the API (application programming interface) development, and write all web services. Backend developers are responsible for overseeing the integration of the frontend code as well.

A backend developer’s career path can be varied. Depending on the type of work they want to do, they can work with full-stack languages such as Python or backend and database languages like Java. 

Some of the most popular programming languages that backend developers use are:

  • Java 

  • HTML

  • PHP

  • Python

  • Javascript

  • SQL

  • Kotlin

Backend developers should also be familiar with at least a few of these frameworks:

  • CSS

  • Django

  • Flask

  • Ruby on Rails

  • Angular

  • Laravel

There is more to the job than technical skills, of course. A successful backend developer excels in these soft skills:

  • Problem solving

  • Flexibility

  • Attention to detail

  • Communication

We’ll explore the necessary skills for a qualified backend developer in more detail further down in the article.

But first, to help you understand how to hire backend developers, we’ll go over this position’s main responsibilities.

Some of the typical tasks that a backend developer deals with are:

backend developer responsibilities explanation graphic

1. Building databases

The foundation of every website and application is where you store the information. A backend developer creates the origin databases and builds caching mechanisms that allow the page to load faster.

2. Building web servers

Servers ensure that the information is pulled from the database and properly displayed on the website.

3. Building security protocols

Backend developers augment databases and servers, making sure the information they store and the process is encrypted and safe. This is especially important when you have to deal with sensitive information, such as passwords or financial data.

4. Writing APIs

API is what connects technology platforms. It’s a necessity in backend development. The most common types of APIs are SOAP (Simple Object Access Protocol) and REST (Representational State Transfer). The main difference between the two is that SOAP uses XML files while REST operates HTML code, which makes it slightly more complicated to work with. 

5. Troubleshooting and debugging applications

A huge part of the backend developer’s job is to maintain the end product’s functionality and ensure any technical issues are dealt with appropriately.

6. Making performance reports

Functionality needs to be tested and tracked down, and backend developers should check the product can perform its key tasks deliver information from the database with the appropriate speed. When bigger or more frequent reports need to be made, a backend developer can code an automated engine for that purpose.

7. Managing backups

Data breaches can be costly – think about the Equifax case, which led to an immediate loss of $5.3 billion in market capitalization.

Research shows that 50% of data loss incidents happen because IT team members make simple mistakes. That’s why hiring a backend developer who can efficiently back up your data and make sure it’s safe and sound is vital.

What skills should a backend developer have?

In this section, we’ll review the skills that every successful backend developer excels at. This includes both hard and soft skills, as both are important for the role. 

It’s important to assess and evaluate how developed these skills are in your candidates. That’s where skills assessments come in handy – they help you create an objective and unbiased hiring process.

You can find some of TestGorilla’s skill tests for backend developers below.

Graphic explaining the skills a backend developer should have

1. Programming languages 

Of course, technical skills come first.

The first thing a backend developer must do is to write clean and effective code. To do that, your developer needs excellent practical knowledge of the programming language they’re using. It’s important to seek an objective and data-driven way to assess your candidates’ capabilities to work with it.

There is a huge variety of programming languages that backend developers may use. Here are some of the most popular.

2. Python

Python is easy to read and can be used for both frontend and backend development, which makes it one of the most used programming languages.

According to a Stack Overflow survey, it was the fastest-growing major programming language in 2019 and second only to Rust as the most loved. 

Another reason for Python’s growing popularity is its compatibility with advanced technologies such as the Internet of Things and Machine Learning. Additionally, it enables developers to use an extensive collection of standard libraries that makes their job easier. 

However, Python is not ideal for application and game development because it consumes more memory and has a slower speed than most programming languages. That’s why it’s mostly used in desktop and web server-side development. 

To evaluate your applicants’ coding skills with Python objectively, your best option is to use the Python Algorithms test. It assesses candidates’ abilities to code a small entry-level algorithm in Python.

The task is straightforward and timed – any backend developer with core Python skills will be able to finish it in less than 10 minutes. For more difficult Python challenges, you may try the Python Data Structures & Objects test or the Python Debugging test

3. Javascript

The main difference between Java and JavaScript is that, while Java is an OOP programming language, JavaScript is an OOP programming script. This makes Java usable for making web and mobile applications, while JavaScript is primarily used on HTML documents and browsers. They also require different plug-ins. 

JavaScript is one of the fundamental technologies on the Internet. It enables developers to create animated images and manage multimedia. JavaScript is well-known for its speed, due to the fact that it’s an interpreted language and cuts down on the time needed for compilation. Another advantage of coding with JavaScript is its interoperability – it can integrate seamlessly with other languages. 

Even though JavaScript has its downsides, such as difficult debugging, it’s still one of the main reasons we see so many interactive and dynamic pages online.

The Javascript Algorithm test will help you evaluate your applicants’ JavaScript knowledge objectively. It presents a straightforward coding task to your candidates. Then, the code is evaluated against a set of test cases, some of which are available to your applicant so they can determine if they’re on the right track. 

Alternatively, to test your future backend developer’s skills further, try the JavaScript Debugging test.

4. Java

Java is one of the most commonly used programming languages – more than 6 million developers work with it. And it’s not just a language but also a software platform. There are few technologies that have managed to stay relevant for over 20 years, but Java is still alive and kicking. 

It came as a refreshing alternative to C’s procedural and platform-dependent code. Java proved that object-oriented coding can be just as efficient and that flexibility is important when it comes to programming. 

Another groundbreaking change that Java brought to the programming world is making TDD (Test-Driven Development) the standard practice for software development and not just an experimental feature. One of Java’s biggest contributions is the introduction of jUnit in 2000. 

Without Java, the world of software development certainly wouldn’t be what it is now. 

One that that made Java so popular is that it’s a high level language, which means that it resembles human languages. It can be converted by using compilers or interpreters, making it easier to read and use. Java has a simple syntax and a mild learning curve, which makes it a preferred choice for many beginner developers. 

Of course, this doesn’t mean Java has no drawbacks. Some, for example, criticize is its speed. Most high-level languages can perform poorly due to the compilation and abstraction level of a virtual machine – Java is no different, and developers must plan carefully to deal with problems and avoid severe underperformance. 

It takes 10 minutes to evaluate your candidates on entry-level Java skills with the Java Algorithm test. To take this one step further, implement the Java Data Structures test to assess whether they can effectively manipulate core data structures written in Java, or the Java Debugging test to determine their abilities to fix a partially broken script. 

5. Kotlin

Kotlin is an open-source programming language that generates code that can run on the Java virtual machine. It was introduced back in 2011, but it gained a lot of traction globally when it was officially declared a first-class Android development language in 2017. 

It’s well-liked due to its compact and intuitive syntax, allowing you to do the same work with fewer lines of code and, therefore, spend less time on the task.

Kotlin is positioned as a 100% Java interoperable language. Rough estimates indicate that, compared to Java, Kotlin cuts the number of lines of code by approximately 40%. 

However, its speed can fluctuate depending on the task – while Kotlin is undeniably faster when it comes to performing incremental builds, for example, Java’s speed is better if you want to build clean Android apps.

The Kotlin test assesses your candidates’ skills in working with Kotlin arrays by providing them with a task to develop algorithms that have to satisfy certain requirements. It also gives them a few examples to illustrate how the function should behave, and the candidates have to solve them. 

6. Ruby

Ruby is a dynamic open-source programming language with an easy-to-read syntax. It’s object-oriented, which means it breaks out pieces of code into objects that can be reused – it organizes software design around data or objects, as opposed to functions or logic.

Ruby’s creator, Yukihiro Matsumoto, wanted to develop a language that leverages object-oriented coding and increases the efficient reusing of code to make programming faster. 

In fact, Ruby was made to be a language that minimizes the lines of code while remaining easily readable and efficient. It can automate repetitive tasks and can be used to build both websites and mobile apps. Ruby uses agile methodology, so development and testing are done simultaneously – a section is tested as it’s written. This makes coding with Ruby quite time efficient. 

One of the biggest disadvantages of Ruby is its lack of flexibility. It follows paradigms and rules quite strictly, making it hard to change the core codebase. This results in flexibility losses because many configured objects can’t be modified later by developers. 

Try the Ruby Debugging test to evaluate your candidates’ skills in working with this language. The test is especially suitable for senior developers because it requires advanced knowledge of Ruby. It gives your candidate 30 minutes to fix a partially working script written in Ruby. 

7. TypeScript

Typescript is a superset of JavaScript, which means it has all its functionality and more. The main difference between the two is that TypeScript gives you more control over your code with the help of type annotations, interfaces, and classes.

Unlike JavaScript, TypeScript uses static typing. This means it acts like spellcheck for your code, showing you where there are errors without changing them for you. Research has found TypeScript detects 15% of common bugs at the compile stage. 

According to GitHub, TypeScript is among the top ten most wanted programming languages in 2020. It’s especially powerful when used for large-scale projects in which many teams have to work together.

Another feature that makes it convenient to use is its rich IDE support. TypeScript is supported by many EDIs, including:

  • Microsoft Visual Studio

  • WebStorm

  • Eclipse

  • Atom

  • CATS

But TypeScript’s strength is also its weakness – since it was built to enable better control than JavaScript through a strong typing system over an inherently dynamic code, it’s not as flexible as JavaScript. Some commonly used classes, such as mixins, can be difficult to use in TypeScript. 

You can evaluate your future backend developer’s skills in coding with TypeScript by implementing the TypeScript Algorithm test or the TypeScript Debugging test in your hiring process. 

8. SQL

SQL (Structured Query Language) is an excellent programming language for straightforward data storage and transformation. Its syntactic rules are simple and easy to follow, and it stands out with its high-speed data processing. Querying, manipulating, and calculating data with analytical queries in a relational database can be done at lightning speed. 

It’s almost 50 years old and is well-known among most developers, which means there are many opportunities to collaborate, learn well-established practices, and share tips. SQL is user-friendly, and you can manage the database entirely by using simple keywords such as “SELECT,” “UPDATE”, or “DELETE.” This means there is little to no coding required to use the language. 

However, SQL is not as useful when it comes to managing unstructured or semi-structured data. 

SQLite is very similar to SQL and has most of its functions. The main difference is that, although SQL is a query language used with databases, SQLite is a database that can be moved around and enables programs to deal with data without the overhead usually associated with specialized database-management systems. It’s built on a serverless structure, which allows any process to access the database disk files directly. 

The entry-level SQLite Database Operations test lets you evaluate your applicants’ skills in manipulating the data. For senior backend developers, you can use the intermediate SQLite Querying test

9. Git

There is more to backend development than knowledge of the programming languages that you’re using. One of the skills that any average developer should have is practical knowledge of Git, the open-source version control system that has now become the standard. 

Originally, Git was created to help developers work in collaborative teams on bigger projects. However, the data science community redirected its purpose, and in addition to using it for source code, you can also manage the collections of files that make up the typical data projects. 

Good knowledge of Git means that your backend developer can perform essential tasks for the execution of any project, such as:

  • Tracking any changes in code

  • Working efficiently in a team with minimal time spent on making sure you’re on the same page

  • Branching without losing track of things

  • Maintaining the integrity of their code because Git protects it cryptographically with the SHA1 algorithm against accidental and malicious damage.

The Git test enables you to objectively assess your candidates’ knowledge of the Git basics and some of its more advanced functionalities. If they perform well on the assessment, this usually means they have 2-3 years of experience with Git and a good understanding of how it works. 

10. Clean code

“Simplicity is the key to brilliance,” as Bruce Lee once said. This applies to many areas in life, including programming.

Writing clean and simple code is one of the most important skills a developer can have. Clean code is easy to read and edit, making it flexible and easy to correct. 

Indeed, clean code can make all the difference when you need to complete a task quickly, so you can avoid wasting precious resources on multiple attempts. It’s especially important for backend developers because they build the product’s structure. If things get too complicated at the base, working with them at later stages of the process becomes even heavier. 

The Clean Code test will help you evaluate a developer’s ability to write code that is easy to maintain and debug. It uses language-agnostic questions to determine whether your candidates are well-acquainted with the SOLID, DRY, and YAGNI principles, which are fundamental for any software engineer. The assessment goes by the traditional definition of “clean code” from Robert C. Martin. 

11. Problem solving 

Problems will arise in any area of work. Solving them effectively is particularly important when your job involves managing constantly shifting variables with strict deadlines. 

Being good at problem solving isn’t just using logic and thinking critically – it’s also about thinking creatively and outside of the box, as well as taking responsibility for your actions. It takes some anticipation, too. You need to foresee future problems, planning ahead to fix them as soon as possible. 

Since problem solving is such a complex skill, it can be hard to determine how developed your applicants are, especially judging from a short resume or brief interview. Sure, you can always ask someone, “Are you good at solving problems?” But can you just take someone’s word for it?

After all, problem solving requires a fair amount of analytical skills, creative thinking, level-headedness, flexibility, initiative, and a lateral mindset – all of which are difficult skills to assess objectively. 

A good solution for evaluating soft skills is to use skills assessments. The Problem Solving test can help you identify candidates who can solve problems efficiently and respond quickly to complex situations. It presents the candidates with typical problem-solving scenarios and draws conclusions based on textual and numerical information. 

12. Attention to detail (textual)

There are many reasons why attention to detail is vital for your organization. A detail-oriented mind will help professionals excel at their jobs. 

Textual details are especially important for developers because a small mistake in your code can make all the difference between a successful project and one that costs your company a fortune. Being mindful of errors is a priceless skill in any field of work. 

Test your candidates’ abilities to process textual information and arrive at the correct answer without losing sight of the details by using the Attention to Detail (textual) test. It can help you identify applicants who are thorough in their work and consider everything before they set their minds on a course of action. 

13. Critical thinking

Critical thinking is one of those things that everyone believes they excel at, but no one is quite able to describe what it is.

Is it the ability to think logically? Or is it drawing the right conclusions from a certain amount of information? Is it a natural disposition to be skeptical of things unless you have solid proof? 

Michael Steven and Richard Paul describe critical thinking as “the intellectually disciplined process of actively and skillfully conceptualizing, applying, analyzing, synthesizing, and/or evaluating information gathered from, or generated by, observation, experience, reflection, reasoning, or communication, as a guide to belief and action.” 

Evaluating such a complex skill can be quite a difficult task. The Critical Thinking test will help you assess your applicants’ abilities to use deductive reasoning, interpret sequences and arrangements, and reach sound conclusions, as well as see the difference between a logical conclusion and an assumption. Candidates who score high on this assessment also possess a well-trained working memory.

14. Time management

Backend development is a complicated process involving many unknown variables and dependencies. You can easily get entangled in this mess and lose track of your priorities. In this role, it’s crucial to be organized and mindful of your time because the people working on the frontend part of the product depend on you to remain on schedule. 

Figuring out which of your candidates have good organizational and planning skills is one of the most difficult tasks for any HR specialist. It’s not something you can read on one’s qualifications.

However, this is where TestGorilla’s Time Management test comes in handy. It evaluates your candidate’s skills in prioritizing tasks based on their urgency, importance, and impact. 

15. Communication 

Backend developers have opportunities to work independently, but more often than not, they have to communicate with other people and teams. Collaboration and teamwork are just as important as good knowledge of programming languages. 

Communicating well isn’t just about getting along with coworkers. It’s about the ability to express yourself clearly and effectively while maintaining professional etiquette and listening to others attentively. 

Can you identify the parts of what someone told you that you didn’t grasp? Can you formulate a concise question that will pin down exactly what needs to be clarified? Were there any non-verbal cues that could’ve indicated what a person meant?

The Communication test will help you determine the answers to those questions for each of your candidates. Remember: communication is key in the workplace! 

How can you hire a backend developer? A step-by-step guide

After you’re familiar with the skills you might look for in a qualified backend developer, it’s time to start hiring!

Follow these ten steps to make the recruitment process as quick and organized as possible.

1. Define the open position’s requirements and responsibilities.

Before you decide which skills are most important for the role, you have to determine what you expect from your backend developer.

What kind of projects will they work on? Will they be mostly working on websites or mobile applications? What do you want them to achieve? What does the job require? Will they be responsible for other people?

Are the projects long-term or short-term? What level of experience do you need for those projects? Define your benchmarks clearly and concisely. 

2. Prepare a job ad and post it on relevant job boards.

The clearer you write, the more effectively you will attract the right crowd, so you don’t have to review too many candidates that don’t fit your criteria.

It’s a good idea to separate the job ad into five sections:

  • Company profile

  • Job description

  • Key responsibilities

  • Requirements

  • Benefits of the job

3. Define which skills you’d like to assess, and prepare a skills assessment.

Skills assessments consist of up to five tests. Use the list of requirements and responsibilities that you made in step one to determine which skills will be most valuable for your backend developer.

What programming languages will they be working with? Will they be in a leading role? Are you putting them in a big team? 

4. Invite applicants to complete the skills assessment.

To direct the candidates to your assessment, you can put the link in the job description. Alternatively, you can email invitations to them directly or use your ATS (Applicant Tracking System).  

5. Review the results to identify your top candidates and invite them to an interview.

Take a look at how many applicants have completed each assessment and see how they score. The tests have time limits and built-in cheating prevention, so you don’t have to worry about the reliability of the results.

Compare the scores with the benchmarks you have set, but don’t be quick to judge. If a candidate has an overall low score, then this is probably not a good sign; but if they score low on one assessment only, you can discuss that at the interview and see how that individual can develop that area.

6. Conduct structured interviews.

Prepare questions for the interview and use the results from the skills assessments to ask applicants more specific questions about their strengths and weaknesses.

To be as organized and efficient as possible, take a look at TestGorilla’s step-by-step guide on how to conduct a structured interview

7. Evaluate all the data you’ve collected and make a decision.

You have an objective evaluation of your applicants’ skills and have had the chance to get a first impression of them during the interview. It’s time to set your mind on the right candidate for your company. You have all the necessary information!

8. Extend an offer to the selected applicant.

Negotiate all final details and a start date.

9. Inform unsuccessful applicants of your decision.

Make sure to inform the remaining candidates that you won’t be working together and thank them for their time. 

10. Begin onboarding.

The job isn’t finished when the hiring is done. Onboarding can make or break a new hire, as HBR claims.

And you’re in it for the long haul – according to Gallup’s “Creating an Exceptional Onboarding Journey for New Employees” report, onboarding a new employee until they reach their full potential takes around twelve months.

You can also use skills assessments to create tailored training programs for every new hire (or even your existing employees). An individual approach promises good results – analyze their strengths and weaknesses now that you have the data and base the program on their specific skills and needs.

Hire the perfect match with an objective, data-driven hiring process

People rarely see the things that backend developers build, but without them many technological features we enjoy and make life easier wouldn’t exist. As technology develops, businesses need more people who understand how to create tech advancements and structures. 

Hire wisely and use all tools at your disposal. Although you can avoid making mistakes entirely when recruiting, an objective, data-driven hiring process that uses the best recruitment tools – like skills tests and structured interviews – will help you find the right candidate for your company. 

Get started for free today and start making better hiring decisions, faster and bias-free.


  1. Companies now face an urgent choice: go digital, or go bust. World Economic Forum. Retrieved on September 30, 2022

  2. The Software Developer Shortage in the US and the Global Tech Talent Shortage in 2022. Grid Dynamics. Retrieved on September 30, 2022

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