10 Innovative Ideas for Node.js Test Assignments to Assess Developer Skills

Node.js has emerged as a cornerstone technology in modern web development, prized for its event-driven, non-blocking I/O model that enhances efficiency and scalability. Built on Chrome’s V8 JavaScript engine, Node.js enables server-side JavaScript execution, allowing developers to utilize a single language across the full stack. When adopting Node.js for real-time applications, microservices architectures, and RESTful APIs, which is especially true for companies aiming to create scalable and high-performance solutions, it is crucial to hire skilled developers who can effectively leverage the potential of this technology. 

One way to identify top Node.js developers is by using targeted test assignments. They help evaluate a candidate’s technical prowess, problem-solving skills, and understanding of Node.js-specific concepts like asynchronous programming, event emitters, and stream handling. They also reveal familiarity with the Node.js ecosystem, including frameworks and database integration. For today’s article, we picked ten effective test assignments to help you find skilled Node.js talent, grouping them into three categories from basic to specialized.

Basic to intermediate test assignments to test Node.js developer skills

Idea 1: Develop a basic CRUD application

When evaluating Node.js developers, a CRUD (Create, Read, Update, Delete) application test can provide valuable insights into a candidate’s skills. This test assesses several key areas:

• Basic Node.js setup: Look for proper environment configuration and project initialization.
• Express.js usage: Evaluate the candidate’s familiarity with Express.js to build server-side applications.
• RESTful API design: Assess their understanding of API principles and implementation.
• Database integration: Check their proficiency in working with databases like MongoDB or MySQL.

Good results: Strong candidates typically demonstrate clean and modular code with a logical project structure, as well as effective use of Express.js middleware and routing. Furthermore, their implementation should include robust error handling and input validation, plus clear and concise API documentation. Efficient database queries and proper error management will also be a strong indicator of their competence.

Red flags: On the other hand, if a candidate struggles with this assignment, it may be evident through disorganized code or inconsistent coding practices. You might notice inefficient error handling or a lack of input validation, which could lead to a subpar user experience. Moreover, missing or inadequate documentation can signal a lack of attention to detail and problems in communicating their work effectively. Poor database integration or query optimization are also potential areas of concern.

Idea 2: Create a RESTful API to manage a to-do list

In this test assignment, we ask candidates to build a RESTful API for a to-do list application. This classic problem might seem simple on the surface, but it actually helps evaluate several key developer skills in Node.js and API development, namely:

• RESTful principles: A candidate’s understanding of RESTful API design and conventions.
• Express.js: Proficiency in using Express.js for building APIs.
• Data persistence: Ability to implement data storage and retrieval using databases.

Good results: Well-performing candidates will strictly adhere to RESTful principles by using meaningful and consistent HTTP status codes. Their code will demonstrate proper data validation and error handling, ensuring that the API is both robust and user-friendly. Efficient and secure database interactions will further confirm their technical expertise.

Red flags: On the flip side, there are some clear signs when a candidate is struggling with this assignment. If they’re not following RESTful conventions—like using GET requests for actions that should be POST or incorrect endpoint naming—that’s a concern. A lack of data validation and error handling leads to a less reliable API, suggesting they might not be thinking about real-world usage scenarios. Inefficient or insecure database interactions can also be a major red flag, pointing to knowledge and skill gaps.

Idea 3: Build a user authentication system

Ask your candidate to develop a user authentication system with registration, login, and password management features. This test assignment helps evaluate the following skills:

• User authentication: In-depth knowledge of implementing secure authentication mechanisms, understanding of different authentication flows and their use cases.
• Security best practices: Awareness of security vulnerabilities, ability to implement countermeasures, and follow OWASP guidelines.
• JWT (JSON web tokens): Understanding of token-based authentication (JWT structure, signing, verification, and secure storage), knowledge of token lifecycle management, and refresh token strategies.
• Session management: Ability to manage user sessions securely, understanding of stateless vs. stateful authentication.

Good results: A well-executed authentication system will showcase secure password hashing using modern algorithms like bcrypt or Argon2, demonstrating the developer’s understanding of security best practices. Proper implementation of JWT for authentication, including secure token generation, storage, and validation, will further indicate their prowess, as will robust session management and proper logout functionality. Comprehensive error handling that provides clear feedback to users without compromising sensitive information is also a positive indicator of a candidate’s attention to detail and user-centric approach. Additional security measures, clean and well-structured code with proper separation of concerns, adherence to DRY principles, and thoughtful UI/UX considerations for authentication flows are clear signs of a professional developer.

Red flags: Insecure password storage (e.g., using outdated algorithms like MD5 or storing passwords in plain text), incorrect or insecure implementation of JWT, such as storing sensitive information in non-encrypted tokens, or mishandling token expiration and refresh are major concerns. Poor session management, including failure to invalidate sessions on logout or not using HTTP-only cookies, and inadequate error handling (exposing too much information in error messages or providing unclear feedback to users) are also significant issues. Lack of input validation and sanitization, leaving the system vulnerable to injection attacks, and failure to implement important security concepts like CSRF protection or secure password reset functionality are major red flags. An overly complex or convoluted code can lead to maintenance issues and introduce security vulnerabilities.

Advanced assignments for Node.js developers

Idea 4: Real-time chat application

Test your Node.js developer’s skills by asking them to implement a real-time chat application using WebSockets. The app could include features such as user presence, message delivery status, support for multiple chat rooms, or direct messaging. Skills assessed will be:

• WebSocket integration: Ability to implement and manage WebSocket connections, understanding of WebSocket protocols, and their advantages over traditional HTTP polling.
• Real-time data handling: Proficiency in handling real-time data updates and broadcasts, including efficient message routing, handling of concurrent messages, and implementing features like typing indicators and read receipts.
• State management: Knowledge of managing application state in real-time environments (synchronizing state across multiple clients, handling race conditions, and ensuring data consistency).
• Performance optimization: Ability to optimize the application for high concurrency and low latency, including implementing techniques like message queuing and load balancing.
• Security considerations: Understanding of security best practices in real-time applications, such as input sanitization, authentication, and authorization in a WebSocket context.

Good results: Successful Node.js developers will handle multiple WebSocket connections efficiently, ensuring smooth and responsive real-time data updates. A key aspect of their work will be implementing proper state management and synchronization, which is crucial for the application’s smooth functioning. Robust error handling and connection management, a scalable architecture, clean code, and advanced features like typing indicators and read receipts will further indicate professional work. These factors will showcase the candidate’s ability to create a seamless and high-performance real-time application.

Red flags: Inefficient or unstable WebSocket connections, poor state management, lack of error handling, scalability issues, security vulnerabilities, overly complex code, neglecting important features, poor performance under high concurrency, and absence of proper testing are red flags to watch out for.

Idea 5: Develop an e-commerce backend

This test assignment sets a task to develop the backend for an e-commerce platform, including product listings, shopping carts, and checkout procedures. Skills assessed will include:

• Complex data relationships: The developer’s ability to model and manage complex data structures.
• Transaction management: Knowledge of handling database transactions securely and efficiently.
• Integration with payment gateways: Experience with integrating and securing payment processes.

Good results: To excel in this assignment, the candidate should demonstrate strong abilities in database design (including thoughtful modeling of product categories, user accounts, and order history), secure transaction management, integration with payment gateways, API design, and performance optimization. Comprehensive error handling and logging will further demonstrate their attention to detail and commitment to reliability, facilitating easier debugging and system health tracking.

Red flags: Potential areas of concern in this assignment include a poorly designed or unnormalized database schema, which can lead to inefficiencies, data redundancy, and integrity issues. This may manifest as repetitive data across tables or a lack of proper relationships between entities like products, orders, and users. Insecure or inefficient transaction handling and inadequate integration with payment gateways (e.g., storing raw credit card data or not implementing proper error handling for payment failures) can compromise the security and reliability of the application. A lack of input validation and sanitization is a serious security risk, and the absence of error handling or logging can indicate a lack of thoroughness and foresight, making the system difficult to debug and maintain.

Idea 6: Design a microservices architecture

The test task would be to design and implement a set of microservices for a hypothetical application. This assignment covers the following areas of expertise:

• Microservices design: The candidate’s ability to design and decouple services.
• Inter-service communication: Knowledge of communication patterns (e.g., REST, message queues).
• API gateways: Understanding of API gateway configuration and management.

Good results: A strong candidate will demonstrate well-defined and decoupled microservices, ensuring that each service operates independently and efficiently. Efficient and reliable inter-service communication, coupled with proper configuration and management of API gateways, will showcase their ability to create a scalable and resilient architecture. These qualities are essential for maintaining performance and reliability in complex systems.

Red flags: Poor design or tightly coupled microservices can undermine the system’s flexibility and scalability. Unreliable or inefficient inter-service communication is also concerning, as it may result in performance issues and system slowdowns. Improperly configured API gateways with security vulnerabilities, as well as fragile or non-scalable architecture, further suggest the candidate might not have the required expertise for the position. Altogether, these issues point to potential gaps in understanding distributed systems design and implementation.

Specialized assignments to evaluate a Node.js developer’s experience

Idea 7: Create a GraphQL API for a blogging platform

This test assignment helps evaluate the following expertise:

• GraphQL schema design: Ability to design efficient and flexible GraphQL schemas.
• Query/mutation implementation: Proficiency in implementing GraphQL queries and mutations.
• Resolver functions: Understanding of resolver logic and performance optimization.

Good results: An efficient and well-designed GraphQL schema will indicate a developer’s understanding of flexible data structures. Properly implemented and documented queries and mutations, along with optimized resolver functions, will further demonstrate their proficiency. Comprehensive error handling and validation are also positive indicators of their thoroughness and attention to detail.

Red flags: Suboptimal or inefficient GraphQL schemas may cause performance bottlenecks and limit system adaptability. If queries and mutations are inconsistent or lack proper documentation, it suggests the candidate may lack attention to detail or communication skills. Resolvers that are not well-optimized can lead to sluggish response times, impacting user experience. The absence of comprehensive error handling or input validation points to potential reliability issues in the implementation.

Idea 8: Implement a serverless function

Ask your candidate to implement a serverless function for a specific task using AWS Lambda or similar services to evaluate their expertise in:

• Serverless architecture: Understanding of serverless principles and deployment.
• Cloud services: Experience with cloud platforms (e.g., AWS, Azure).
• Event-driven programming: Ability to implement and manage event-driven workflows.

Good results: High-performing candidates will create an efficient and scalable serverless function, demonstrating a solid grasp of serverless architecture principles. Their solution should display proper use of cloud services and resources, along with effective handling of events and triggers. A secure and cost-effective design will demonstrate the candidate’s capacity to develop dependable and sustainable solutions.

Red flags: Concerns arise when serverless functions are poorly optimized or unscalable, as they can lead to performance bottlenecks and inflated costs. Suboptimal utilization of cloud services or resources suggests gaps in understanding cloud architecture fundamentals. Ineffective handling of events and triggers may result in unreliable system behavior. Moreover, a design that neglects security considerations or fails to account for cost efficiency indicates a lack of holistic thinking about serverless deployments and optimization.

Idea 9: Automated testing setup

This task assignment would tell a developer to set up automated testing for an existing Node.js project. Skills assessed are:

• Testing frameworks: A developer’s proficiency in testing frameworks (e.g., Mocha, Chai).
• Test coverage: Ability to achieve comprehensive test coverage.
• CI/CD integration: Knowledge of integrating tests into CI/CD pipelines.

Good results: An effectively implemented automated testing framework will include comprehensive and well-structured test cases, achieving high test coverage with minimal redundancy. Seamless incorporation of these tests into CI/CD pipelines will showcase the candidate’s ability to maintain continuous integration and delivery processes. Clear, well-crafted, easy-to-interpret test reports will further demonstrate the candidate’s meticulous approach and commitment to quality.

Red flags: Incomplete or poorly structured test cases can lead to gaps in test coverage and missed bugs. Low test coverage or redundant tests indicate inefficiency and a lack of thoroughness. Poor integration with CI/CD pipelines suggests a lack of understanding of continuous integration and delivery principles. Unclear or uninformative test reports further indicate a lack of attention to detail and communication skills.

Idea 10: Performance optimization of a given Node.js application

Candidates are tasked with improving the performance of a provided Node.js application. Through this task, we can effectively measure a candidate’s practical skills in performance tuning, their analytical approach to problem-solving, and their depth of knowledge in Node.js optimization best practices. Skills assessed:

• Profiling: Ability to profile and analyze application performance.
• Performance bottleneck identification: Skill in identifying and addressing performance bottlenecks.
• Optimization techniques: Knowledge of various optimization strategies and techniques.

Good results: Node.js developers who excel in this task will demonstrate effective use of profiling tools and techniques, pointing to their ability to analyze and improve application performance. Accurate identification and resolution of bottlenecks, leading to significant performance improvements, are strong indicators of their technical proficiency. High-performing candidates will also provide documentation of optimization strategies and results, which is also an indicator of their thoroughness and ability to communicate their work.

Red flags: Ineffective or incorrect use of profiling tools can lead to missed opportunities for optimization. Failure to identify or address performance bottlenecks indicates a lack of analytical skills. Minimal or no performance improvements suggest that the candidate may not possess the necessary optimization techniques. A lack of documentation or explanation of optimizations further indicates a lack of attention to detail and communication skills.

Find the right Node.js developer with Beetroot

Hiring Node.js developers goes beyond simply testing their technical skills; it’s also about finding someone whose values resonate with your company’s values and culture. At Beetroot, we take pride in connecting our clients with the best pre-vetted developers who are passionate about meaningful projects. We specialize in setting up dedicated teams for impactful clients, especially in fields like HealthTech, EdTech, and GreenTech. If you need to boost your development capacity, bring on dedicated developers, or speed up your product’s time to market, we’re here to help.