Hire Pre-vetted Node.js Developers

Node.js is a lightweight JavaScript runtime, mainly used to build network applications such as web APIs or microservices. Since its first release in 2009, this fast-growing platform has powered over 20 million website backend systems. 

Node.js is fast and scalable, which has led to a notable increase in enterprise adoption rates. Names like Amazon, Netflix, eBay, and Reddit come to mind. However, its flexibility, rich ecosystem, and gentle learning curve have made it an ideal contender for smaller organizations that need to move quickly, such as startups and scale-ups.

Node.js developers focus primarily on a system’s backend operations by using a multi-paradigm language such as JavaScript to build web servers. Finding a quality candidate for this job depends on the calibre of performance in these skill sets. This, combined with great interpersonal abilities, makes for an excellent Node.js developer who can add value to projects and overall business goals.

Non-Technical Skills to Assess in a Node.js Developer

A reliable Node.js developer will need strong technical capabilities, but individuals that have specific soft skills can effectively contribute to a product, team, or organization through more than just writing code. 

Below is a list of the most valuable soft skills recommended for a Node.js developer.

Clear Communication and Active Listening

While the typical software developer stereotype depicts a person working in isolation, wearing a set of earphones, this is uncommon in many of today’s workplaces. These days, most developers work in teams that require members to collaborate with managers, stakeholders, users, and colleagues. While coding might remain the main activity for developers, they will also be required to perform many non-technical activities, such as mentoring, collaborating, and receiving feedback. 

Team members, who can convey ideas and exchange information through active listening, often curb miscommunication and errors that lead to additional hours of work required to resolve these errors. These candidates will save the business time and resources, and with excellent communication skills, will be better equipped to drive projects towards completion.

During the interview process, opportunities to evaluate good communication skills are abundant. Face-to-face interviews or videoconferencing provide the best source of feedback and understanding, as the interviewer has access to many social cues, be they verbal or non-verbal. For example, does the candidate listen carefully and not interrupt the interviewer from speaking? How well does the candidate deliver answers to interview questions? Does the candidate ask clarifying questions and positively handle negative feedback? 

Aside from these interviews, other opportunities exist for hiring managers to assess these soft skills, namely email exchanges, networking platforms, or even phone call discussions.

Drive for Self Improvement and Mentoring

Teams of developers at the top of their technical game will ensure quality product outcomes. While many interviews focus on the candidate’s knowledge and experience, the candidate’s affinity for continuous learning can often be overlooked. This is a critical skill in software development because unforeseen technical problems arise and new technologies are required for new project goals. When these issues reveal themselves throughout a project, a developer willing to learn will see this as an opportunity and be able to adapt quickly.

A natural drive for mentoring and helping others is also a great skill in a development team. It can help put everyone on the same page, increase the level of skills in a team, and stimulate collaboration. If a team can improve its skills and knowledge internally, less time and money will be spent on external training workshops and courses.

Some hints to notice a good self-learner can be found before interviews by looking at the candidate’s personal projects on various public repositories, recent certifications achieved, or previous courses they’ve taken. If no information is available prior to the interview, it is always good to ask Node.js candidates what is currently done to keep up-to-date with industry knowledge and skills. It also helps determine which methods the candidate uses to overcome unplanned tasks that require new skill sets.

Time, Deadlines and Pressure Management

Software engineers have to deal with high amounts of pressure and ever-changing deadlines, requirements and scope. Everyone responds differently to stress and friction within their work environments. Some become overly emotional, which can impact the team negatively, while others seem to freeze or shut down and become unproductive.

Gauging someone’s ability to cope with pressure can be somewhat challenging in an interview setting. However, there are some handy questions to ask, for example:

• Can you walk me through a previous situation where you were under an immense amount of pressure?
• How would you approach an XYZ situation?
• What strategies do you employ to help you keep a cool head when dealing with a stressful situation?

Technical Skills to Look For in a Node.js Developer

A good Node.js developer can come with a variety of technical skills. Some of the excellent ones might not have even worked with Node.js before as the Node.js platform is fairly simple to harness and learn by most seasoned backend developers. 

However, what’s more important when interviewing candidates for this role is the context in which Node.js will be used. This is why, as a hiring manager, it is important to understand the project requirements leading up to the interview so that the technical questions can be better targeted. 

Backend Engineering and Architecture

Node.js developers are primarily dedicated to building the backend functionality of applications. Deep knowledge of information architecture and how to best organize and structure services and components is an essential skill needed to ensure cleaner, more extensible code and products that are easier to maintain and hand over. 

You can ask language and framework-agnostic questions to evaluate high-level architectural, problem-solving and quick thinking skills. Some examples include: 

• How do you ensure system scalability?
• How would you architect a system with requirements XYZ?
• How would you split a monolithic application into an event-driven microservice?

It is important to allow the candidate to offer up some ideas during this part of the interview. If possible, provide the candidate with the right tools to prepare and present their ideas in an organized manner.

Environment & Infrastructure

Node.js can be run on most operating systems, environments, and hosting platforms. It is crucial for any node.js developer to have a deep understanding of this language, as it directs the way the application will be built and deployed. 

It is important to narrow this down before the interview to gear the questions toward the project’s specific requirements and not waste time on irrelevant questions. Below is a list of the most common types of platforms that run a node.js application:

• On-premise hosting: Base metal / Virtual Machine / Containers
• Cloud hosting: Virtual Instance / Containers / Serverless
• Cloud providers: AWS, Google Cloud, Azure, Digital Ocean

Web Server/Networking

The candidate must have a good knowledge of networking concepts and the HTTP protocol. It will inform better decisions around project technologies, leading to shortened response times, and improved application security. Below is a list of interview topics to cover to evaluate a candidate’s networking knowledge:

HTTP & Networking basics: 

• Anatomy of an HTTP request: header, body
• HTTP Content Types: JSON, Text, File, Media
• HTTPS: security by encryption using TLS (TCP/IP)

Web Api standards: 

• REST: a de-facto standard for stateless Web APIs 
• GraphQL: a fast-growing standard, which adds enriched query & manipulation language to a standard REST API

Authentication & security:

• JWT: Token-based authentication for stateless APIs such as REST
• OAuth: Open standard for delegating authentication to providers such as Google or Facebook

Programming & Coding Skills

Your project or company will dictate whether the candidate will need to be versed in JavaScript-like languages on top of pure JavaScript. The most popular JavaScriptflavors of the moment are TypeScript, CoffeeScript and Dart.

For programmers with a solid background in other Object-Oriented Programming (OOP) languages, the knowledge gap is easy to fill, and the learning curve is short. This is why it is advisable to never close the door on candidates without commercial JavaScript experience.

You can assess this with a prepared coding assignment. The assignment doesn’t need to be highly complex or challenging, and it has the advantage of evaluating some basic coding skills before the interview. It can also be a suitable medium for code review and discussion during the interview. If you do not feel confident preparing such an assessment, you could ask a senior JavaScript developer from your team to produce one instead. 

Core Node.js Concepts

This is the part where interviewers can evaluate whether an engineer has previously worked with Node.js or not. As we’ve already established, some great engineers without Node.js experience can still be excellent candidates for the role. However, if a candidate wants to take on the role, a minimum requirement should include a brush-up of their Node.js knowledge and conceptual understanding.

Node Core Concepts:

• Node process model: non-blocking asynchronous calls, performance for I/O bound tasks
• Blocking vs non-blocking calls (async)
• Concurrency, single threading, event loop

Node Modules:

• Core modules: modules available on node.js, such as crypto (encryption), fs (file handling) or HTTP (web server utilities).
• Local modules: components or libraries created by developers
• Third party modules: external dependencies packages managed by npm

Common Node Frameworks:

• Express: a popular library bringing many tools and utilities for web server capabilities.
• Apollo: a framework for building a GraphQL web server.
• Hapi: a framework to build web server applications out of the box.

Technical Interview Questions for Node.js Developers

Question: Which use case is the least suited for Node.js?

• Machine learning processes

• Web Server

• Microservices

• Event driven applications

Answer: Machine learning processes

Question: Which of the following languages cannot be used in node.js applications?

• Typescript

• Javascript

• Coffeescript

• Python

Answer: Python

Question: Where does a node.js project store its dependencies?

• project.json

• package.json

• composer.json

• require.json

Answer: package.json

Question: Which library is used for unit testing in node.js?

• jest

• yarn

• junit

• babel

Answer: Jest

Question: Which best describes async/await?

• Syntaxic sugar to turn promises into imperative code

• Library for HTTP requests processing

• Node.js core dependency injection mechanism

• Typescript’s library for file handling

Answer: Syntaxic sugar to turn promises into imperative code

Final Thoughts

Because Node.js is usually the main backend of a web application for an organization, it is crucial to find the right developer to build and maintain the platform. Finding a suitable candidate with a deep knowledge of programming, backend architecture, and the software development life cycle is essential, and so is a great attitude, good communications skills, and an eagerness to learn. These are key to maintaining a successful future in this role within a business, project, or contract.

In a candidate interview, preparation is key to success, and this applies to the candidate and the hiring manager. Covering the technical and interpersonal aspects of the role within this guide will provide you with reliable tools to prepare for Node.js developer interviews.