Hire the Top 3% of Freelance JavaScript Developers

JavaScript Developer Demand Continues to Dominate the Market

In today’s rapidly evolving technology landscape, hiring the right talent is more important than ever—which is especially true when it comes to JavaScript, the leading language for websites and web apps. Furthermore, when hiring a JavaScript developer, you’re not just looking for one skill: A diverse set of additional skills is required, the combination of which is highly dependent on each project. With this high demand for a complex skill set, it can be very challenging to find the right candidate.

According to the 2023 Stack Overflow Developer Survey, JavaScript continues to dominate the programming landscape for the 11th year running: 66% of professional developers use it. This immense popularity can be attributed to its versatility, ease of use, and robust ecosystem. With the advent of front-end frameworks and libraries such as React and Vue.js, as well as back-end ecosystems such as Node.js, JavaScript’s reach has expanded far beyond the browser to server-side and even mobile application development.

As the language expands and the ecosystem improves, demand for skilled JavaScript developers increases. The US Bureau of Labor Statistics predicts that employment of web developers—largely including those proficient in JavaScript—will grow 23% for the decade ending in 2031, much faster than the overall average and nearly triple the rate from 2021. This increasing demand, coupled with a limited pool of experienced JavaScript developers, has made hiring for this role particularly challenging for employers.

In this guide, we discuss the essential skills and knowledge a proficient JavaScript developer should possess, as well as the significance of understanding popular frameworks and libraries. We delve into strategies for identifying candidates, such as crafting effective job descriptions, leveraging online assessments, and evaluating their problem-solving abilities, to find developers who can excel in your organization. Additionally, we explore best practices for onboarding and retaining top talent.

What attributes distinguish quality JavaScript Developers from others?

JavaScript is ubiquitous; therefore, JavaScript developers are ubiquitous as well. However, the sector in which JavaScript has its firmest grip is web development, both for the front end (the website as the user sees it) and the back end (what happens behind the scenes). Since there is limited overlap between the skills required for front- and back-end development, JavaScript roles are commonly separated along those lines:

Front End

A front-end developer typically uses a framework like React, Vue.js, or Angular, together with components and raw CSS, JavaScript, and HTML, in order to create the user-facing portion of a project. Front-end developers can complete some projects themselves—websites that involve no data storage, for example—but in a team context are often complementary to one or more back-end developers.

Back End

A back-end developer deals with all the processes that run on a central server instead of a user’s computer. A developer using JavaScript for back-end development will very often be a Node.js developer. Back-end developers are also responsible for databases, APIs, and user authentication. Nowadays, their code usually runs in the cloud, so experience with cloud platforms and deployment is a key skill to look for in candidates.

Full Stack

A full-stack developer is versed in both front- and back-end development. Usually, it takes time to become so well rounded. However, with the vast number of frameworks and libraries available, it has become more and more achievable to be a full-stack JavaScript developer without having accrued many years of experience. Note: While full-stack developers have a breadth of knowledge, it’s typical for some candidates to be stronger in front-end development while others will be stronger in back-end development. Be sure to understand your needs to ensure you hire the best candidate for your project.

Simply put, finding a quality JavaScript developer with the right expertise is key to transforming your project idea into reality.

How can you identify the ideal JavaScript Developer for you?

When hiring a JavaScript developer, it’s essential to consider their technical expertise, problem-solving abilities, and experience with relevant frameworks and libraries. The best JavaScript developers have not only a large portfolio and a track record of delivering high-quality projects, but also modern coding habits in line with the evolution of ECMAScript—JavaScript’s formal specification.

There is no one-size-fits-all approach to identifying the perfect candidate for your project, but these are the three most important aspects to take into consideration:

To summarize, start your hiring process by clearly defining your project’s needs, skills gap, and problem statement(s). Then use that context to inform the level of developer you will hire. If your project requires starting from scratch or designing a new core feature, investing in expert talent is justified. However, for less-complex tasks or when working with a limited budget, a junior developer who will have adequate supervision or a mid-level developer with previous experience in the right skills can be a cost-effective solution.

Regardless of project context, there are many common skills to be aware of for anyone looking to hire JavaScript programmers:

Understanding of JavaScript syntax and data structures, such as arrays and objects, is the most basic requirement of a JavaScript developer—they cannot write code without it.

Knowledge of asynchronous programming, event handling, and callbacks is very important, allowing apps to accomplish tasks in parallel. When working with web technology in particular, developers will use external connections often, e.g., to fetch images from storage, make database requests, and call APIs. Without asynchronous programming, most server requests would cause webpages to take several seconds to load—a surefire way to lose customers.

Understanding of web development concepts, such as REST APIs, HTTP requests, and web security are key elements to look for in both front- and back-end JavaScript developers, as they involve how a website communicates with the back end and receives the required information to display to the user. A skilled developer will be able to implement APIs and security measures to protect applications from threats, ensuring seamless and safe user experiences.

Experience with version control systems, such as Git is a necessity for any developer, including juniors, as it allows collaborating on large teams, tracking code changes (to allow for backtracking), and resolving conflicts, all of which are integral throughout the project lifecycle.

Knowledge of software design patterns and coding best practices allows developers to create maintainable, scalable and, most importantly, readable code, making it easier for other developers to collaborate or take over projects.

The ability to write modular code makes it easier to understand, test, and maintain a large codebase. It allows for easier tracking of issues, simpler updates, and lower likelihood of conflicts between developers’ updates. A typical characteristic of more experienced developers is the ability to write properly modularized code.

Understanding testing and debugging techniques is one of the most important aspects of a developer’s job and also one of the most differentiating attributes between junior and senior developers. Bugs are part of the lifecycle of apps. So a developer should be familiar with standard testing methodology, know how to create a good test environment, and be adept at finding bugs quickly.

There are three more key skills that only apply to front-end development:

HTML, CSS, and DOM manipulation are the building blocks of the design of a website, and any front-end developer candidate should be experienced in using them. DOM manipulation encapsulates changes to a website that are visible to the user, e.g., animations or single-page apps. Even with modern frameworks where these aspects aren’t worked with directly very often, developers still need to know what’s happening behind the scenes to be effective.

Proficiency in using JavaScript frameworks and libraries, such as React, Angular, or Vue requires the ability to leverage these tools to build efficient, scalable, and maintainable web applications. Skilled developers understand the unique features, best practices, and nuances of each framework, enabling them to create interactive user interfaces and optimize application performance. It’s common for developers to concentrate their experience in a particular framework, so it’s worth filtering for this in projects where the framework has already been chosen.

Familiarity with browser compatibility issues and cross-browser testing involves understanding the differences among browsers and their rendering engines. Skilled developers address these discrepancies and perform cross-browser testing to ensure consistent user experiences across various platforms, devices, and browser versions, optimizing the application’s accessibility and reach.

Now that you know what you’re looking for among JavaScript developers for hire, you’re ready to craft a job description.

How to Write a JavaScript Developer Job Description for Your Project

Start with a solid template and include as many details as possible to try to narrow the channel of prospective applicants and thereby avoid drowning in applications. Here are some specific points you might include about your project to help applicants appropriately—but not too zealously—self-select:

• The tech stack, tools, and industry
• Whether the project is new or in process
• The estimated length of the project
• The expected outcome
• The current team’s skills and gaps
• Whether you are looking to hire full-time, part-time, or freelance JavaScript developers
• Whether the position is remote, partly remote, or fully on-site

Companies looking to hire JavaScript developers may also want to approach the job description as one for:

• Back-end, front-end, or full-stack developers.
• Specialists in a specific framework like React.
• Those with particular skills like QA engineering.
• Some combination of these and other roles.

What are the most important JavaScript Developer interview questions?

Interviews are more likely to yield a more balanced assessment if they include a mix of contextual questions—higher-level discussions about a project’s technical decisions or issues encountered—and more technical questions like these:

What is the difference between the concepts of null and undefined in JavaScript? And how do you handle them?

Null represents an intentional absence of any object value, while undefined represents a variable that has been declared but has not been assigned a value.

If a developer doesn’t need to know whether the variable is null or undefined, they can use a standard equality check against null; if they do, they’ll need a strict equality check. A good follow-up question: Ask the candidate to explain a time when they faced a situation needing a null check and the reasoning behind whether it needed to be strict or not.

What is the difference between the equality (==) and strict equality (===) operator? When should you use which?

The equality operator performs type coercion, which means it attempts to convert the operands to a common type before making the comparison. The strict equality operator never converts before comparing.

The equality operator is quite dangerous to use and is generally frowned upon since it can yield unexpected results, like the fact that an empty string is considered equal to the number zero when the two are coerced to the same type.

What are the differences between let, const, and var in JavaScript?

var is function-scoped and can be redeclared and reassigned. let and const are block-scoped, and let allows reassignment, while const does not.

It can also be fruitful to discuss a candidate’s choice of various tools and libraries for your upcoming JavaScript use cases.

Lastly, as with the job description, it’s worth including questions about more specific technologies, e.g. Node.js, that are pertinent to your project.

Why do companies hire JavaScript Developers?

Businesses could leverage just about any programming language. What are the main features of JavaScript? What benefits does it provide over other languages? How does it help companies improve their bottom lines?

JavaScript is a general-purpose programming language that has gained a large part of the digital market. Increasingly, projects can be written from start to finish using only JavaScript: front end, back end, authentication, data processing, and more. The websites and digital products you use on a daily basis very likely use JavaScript as one of their main languages.

Uniformity Benefits

The language’s key attribute is its versatility, enabling developers to work seamlessly within a project where every component in the stack uses the same language. This uniformity promotes efficient resource sharing and simplifies development processes. For example, data validation is often done on both the front end (for a performant user experience) and the back end (for security). JavaScript lets both implementations use the same file, rather than a pair of files that can easily end up an out-of-sync source of security holes and user-repelling bugs.

However, the extensive scope of the language has inevitably led to numerous specializations, each with their own frameworks, libraries, and conventions. Hiring managers who understand this nuance are a great asset. For example, they’ll know that a React programmer has a better chance than an Express.js specialist at short-term effectiveness on a React Native project—even though anyone looking to hire JavaScript developers will see résumés with varying combinations of the three.

If you find yourself in the early stages of the hiring or architectural processes, you may still be considering the merits of JavaScript versus Java, TypeScript, Python, and/or PHP. How do you know which programming language is best for your next project?

All these languages rival JavaScript for web development, and each one has its pros and cons:

• JavaScript versus Java – Java is one of the most common general-purpose development languages. Java has been a back-end option longer than JavaScript, and remains a significant back-end competitor. But to hire a Java developer over a JavaScript developer would negate the aforementioned uniformity benefits—which is equally true for Python and PHP.
• JavaScript versus Python – Python is also very popular as a general-purpose language, particularly for data science and machine learning applications. For larger teams and projects, a Python specialist can leverage these benefits separately from a JavaScript or TypeScript back-end developer.
• JavaScript versus PHP – PHP is an immensely popular language for back-end web development, its primary purpose. WordPress and Laravel’s popularity keep it well ahead of any challengers. Nonetheless, more PHP developers want to work with JavaScript than vice versa.
• JavaScript versus TypeScript – TypeScript is one of the fastest-growing programming languages. TypeScript is a safer version of JavaScript, which should be the preference for any new projects whenever possible. TypeScript can import JavaScript; therefore, a project can mix the two languages, making for a smooth transition and likely explaining its impressive popularity growth. TypeScript is the only language to share the benefits of uniformity with JavaScript. Many JavaScript developers will know TypeScript or be able to pick it up quickly.

But only TypeScript—since its code gets converted to browser-native JavaScript—offers any serious front-end competition so far; Java, PHP, and Python are back-end languages in a web context. This may change, though, as Python can now be executed in the browser through PyScript.

In this guide, we covered several key aspects of JavaScript development and how to use those to your advantage when hiring. We described the difference between the front-end, back-end, and full-stack roles of a JavaScript developer. We also mentioned the key skills and traits to look for when hiring a JavaScript developer and how to gauge the relevance of a candidate’s experience within the vast ecosystem of frameworks and libraries. Finally, we briefly discussed what to include in a job description and interview to maximize each element’s effectiveness.

Whether you’re looking specifically for a TypeScript programmer, a Node.js engineer, an Angular expert, a full-stack developer, or some other JavaScript specialist, you’re now well equipped to find the right match for your project within an impressively broad subfield of software engineering.