Senior Software Engineer - MERN Stack

Relanto; Pune District; On-site; INR 180,000 - 320,000; Full time

Job summary

Relanto is seeking a senior full-stack developer to design, build, and manage API integrations at scale. You will work on backend services with Node.js and frontend apps with React.js or TypeScript frameworks, focusing on scalable systems and end-to-end feature ownership.

Key responsibilities include designing REST APIs, integrating with external systems, implementing secure authentication, and ensuring robust logging and monitoring. Collaboration with product, QA, and DevOps teams is essential.

Qualifications

• 8+ years of software development experience.
• Strong expertise in Node.js.
• Hands-on experience with React.js or TypeScript-based frontend frameworks.
• Proven experience designing and implementing REST APIs.
• Strong experience with third-party API integrations.

Responsibilities

• Design and develop scalable backend services using Node.js.
• Build and maintain RESTful APIs and integration layers with external systems.
• Develop frontend applications using React.js or TypeScript-based frameworks.
• Own end-to-end feature development across backend and frontend.
• Design and implement API integrations with third-party platforms and internal services.
• Handle webhooks, event-driven architectures, and async processing.
• Ensure security, authentication (OAuth/JWT), and data protection.
• Implement logging, monitoring, and performance optimization.
• Work with product, QA, and DevOps teams for delivery.
• Mentor junior developers and drive engineering best practices.

Skills

Node.js

React.js

TypeScript

API Design

Security best practices

Tools

MongoDB

AWS

Azure

GCP

CI/CD

Job description

Full-Time

Role Overview:

We are looking for a senior full-stack developer with strong expertise in building and managing API integrations at scale. This is a full-stack role involving both backend service development and frontend application development, with a strong focus on scalable systems and API integrations.

Key Responsibilities:

• Design and develop scalable backend services using Node.js.
• Build and maintain RESTful APIs and integration layers with external systems.
• Develop frontend applications using React.js (or TypeScript-based frameworks).
• Own end-to-end feature development across backend and frontend.
• Design and implement API integrations with third-party platforms and internal services.
• Handle webhooks, event-driven architectures, and async processing.
• Ensure security, authentication (OAuth/JWT), and data protection.
• Implement logging, monitoring, and performance optimization.
• Work closely with product, QA, and DevOps teams for delivery.
• Mentor junior developers and drive engineering best practices.

Required Skills:

Core Stack

• 8+ years of software development experience
• Strong expertise in Node.js (must-have)
• Hands-on experience with React.js or TypeScript-based frontend frameworks

API & Integration

• Proven experience designing and implementing REST APIs
• Strong experience with third-party API integrations
• Hands-on experience with:
• Rate limiting, retries, and fault tolerance
• Experience working with external platforms (payments, SaaS tools, enterprise systems, etc.)
• Strong understanding of asynchronous programming and event-driven architecture
• Experience with database design (MongoDB or other NoSQL/SQL)
• Ability to build scalable, high-performance services

Security

• Strong understanding of OAuth 2.0
• JWT-based authentication
• Secure API design and data handling
• Experience with AWS / Azure / GCP
• Familiarity with CI/CD pipelines
• Experience with logging, monitoring, and observability tools