Senior Node.js Backend Engineer - Remote

Kumaran Systems; United States; Remote; USD 120,000 - 180,000; Full time

Job summary

Kumaran Systems is seeking a Node.js Backend Developer with 4-7 years of experience to design, implement, and maintain secure, scalable backend services and RESTful APIs. You will work with MongoDB/Mongoose, implement JWT-based authentication, and collaborate with DevOps on CI/CD pipelines in a fully remote setup.

The role emphasizes modernizing legacy code, secure coding practices, and integrating with internal/external systems. Strong focus on performance, reliability, and data modeling.

Qualifications

• Hands-on experience with Node.js and modern asynchronous JavaScript (Promises, async/await).
• Deep experience with Express.js (routing, middleware, validation, centralized error handling).
• Proven track record building and consuming RESTful APIs in production environments.
• Practical, hands-on experience with MongoDB and Mongoose.
• Experience implementing JWT-based authentication and role-based access control.
• Good understanding of web security: secure cookies, session management, CSRF, CORS, token lifecycle, and OWASP vulnerabilities.
• Experience integrating downstream APIs using Axios or similar HTTP clients.
• Experience with TLS/SSL certificates, timeouts, resilience patterns, and troubleshooting service-to-service communication.
• Experience writing unit tests with Jest, including mocks and async test cases.
• Working knowledge of Git workflows and CI/CD pipelines.

Responsibilities

• Design, develop, and enhance backend services using Node.js, JavaScript, and Express.js.
• Own the design and maintenance of secure, scalable REST APIs and middleware.
• Model and manage data using MongoDB and Mongoose (schemas, indexes, queries, transactions).
• Implement and maintain authentication/authorization with JWT, secure cookies, sessions, roles, and permissions.
• Enforce secure coding practices: validation, error handling, logging, audit trails, and consistent API responses.
• Integrate with internal/external systems using Axios/HTTP clients, TLS/SSL, and API gateways (e.g., Azure API Management).
• Handle secure file upload/download flows (Busboy, MongoDB GridFS) with proper validation and sanitization.
• Write and maintain unit and integration tests using Jest; help improve test coverage and reliability.
• Collaborate with DevOps teams on CI/CD pipelines (Jenkins, Git, Artifactory, SonarQube, Fortify, Black Duck).
• Incrementally refactor and modernize legacy code while preserving business functionality.

Skills

Node.js

Express.js

MongoDB

JavaScript

JWT authentication

RESTful APIs

Tools

Mongoose

Jest

Git

Job description

Kumaran Systems is seeking a Node.js Backend Developer with 4-7 years of experience to design, implement, and maintain secure, scalable backend services and RESTful APIs. You will work with MongoDB/Mongoose, implement JWT-based authentication, and collaborate with DevOps on CI/CD pipelines in a fully remote setup.

The role emphasizes modernizing legacy code, secure coding practices, and integrating with internal/external systems. Strong focus on performance, reliability, and data modeling.