Fullstack Developer- III (MERN with Websocket)

Zealant Consulting Group; Bengaluru; On-site; INR 2,500,000 - 4,200,000; Full time

Job summary

Zealant Consulting Group is seeking a highly skilled Tech Lead/Product Developer- III to own and evolve MERN stack applications across multiple SaaS products. You will drive architecture, code quality, and AI-enabled features while guiding a cross-functional team.

You will balance individual contributor duties with leadership, shaping development practices, documentation, and deployment pipelines to deliver robust, scalable software in a fast-paced startup environment.

Qualifications

• 6-8 years of hands-on full-stack development experience with MERN stack.
• Proven ability to lead or architect multi-module SaaS products in startup environments.
• Strong API design and documentation skills, with focus on scalability and maintainability.

Responsibilities

• Take complete technical ownership of MERN stack applications, analyze, debug, and enhance existing code.
• Architect and implement scalable, modular solutions across all products.
• Collaborate with Product Manager to translate business goals into technical execution plans.
• Drive AI and automation integrations (LLMs, NLP, chatbots) into systems.
• Create and enforce detailed API documentation, architecture diagrams, and deployment processes.
• Own CI/CD, version control, code reviews, and performance optimization.
• Identify and fix scalability, performance, and security gaps proactively.
• Ensure alignment between tech roadmap and product vision.
• Champion testing, deployment, and code quality best practices.

Skills

MERN stack

WebSocket

Kafka

REST APIs

Microservices

AI integrations

CI/CD

Cloud platforms (AWS/GCP/Azure)

Technical leadership

Tools

Postman

Swagger

Jira

Job description

Experience : Min. 6 - 8 Yrs

We’re looking for a Tech Lead who is not just a coder but a builder, problem solver, and leader. Someone who can dive deep into an existing codebase built on the MERN stack, understand it with zero knowledge transfer, and drive innovation and structure from day one.

Interview Process

R1- AI Interview Assesment

R2- Panel round Technical

R3- F2F with founders

R4- HR Culture fit / salary Discussion

Position Name: Product Developer- III

Experience : Min. 6 - 8 Yrs

We’re looking for a Tech Lead who is not just a coder but a builder, problem solver, and leader. Someone who can dive deep into an existing codebase built on the MERN stack, understand it with zero knowledge transfer, and drive innovation and structure from day one.

This is a hands-on leadership role. You’ll act as both Individual Contributor and Technical Lead, managing architecture, code quality, scalability, and AI integrations across all six products of our Client.

You’ll collaborate closely with the Product and QA Leads to ensure speed, structure, and flawless execution while building robust documentation and engineering discipline from the ground up.

EXCITED ABOUT YOUR TASKS?

• Take complete technical ownership of the MERN stack applications develop, analyze, debug, and enhance existing code without prior knowledge transfer.
• Architect and implement scalable, modular, and maintainable solutions across all products
• Collaborate with the Product Manager to translate business goals into technical execution plans.
• Drive AI and automation integrations (e.g., LLMs, NLP, chatbots, analytics) into existing systems.
• Create and enforce detailed documentation code structure, APIs, architecture diagrams, deployment processes.
• Own CI/CD, version control, code reviews, and performance optimization.
• Identify and fix scalability, performance, and security gaps proactively.
• Ensure strong alignment between tech roadmap and product vision.
• Bring in best practices for testing, deployment, and code documentation.

WHAT WILL YOU NEED TO SUCCEED?

• 5-8 years of hands-on experience in full-stack development, with strong focus on the MERN stack (MongoDB, Express.js, React.js, Node.js).
• Strong experience on WebSocket / Socket programming is a must. Websocket is mandatory
• Strong knowledge of Kafka, Nginx, or GraphQL.
• Proven experience leading or architecting multi-module SaaS products in Startup environments.
• Strong command over REST APIs, Microservices, and asynchronous architecture.
• Expert in building AI-powered products using AI agents and use of modern vibe coding workflows to rapidly prototype and scale intelligent applications.
• Exposure to AI/ML or 3rd Party integration using APIs or SDKs (OpenAI, Hugging Face, LangChain, TensorFlow, etc.).
• Understanding of DevOps, CI/CD, and cloud platforms (AWS, GCP, or Azure).
• Deep passion for processes, API documentation, and clean code.
• Strong debugging and reverse-engineering skills, ability to understand complex systems quickly. Ability to balance IC responsibilities with team leadership.
• Familiarity with Agile, Jira, Git, and API documentation tools like Postman or Swagger.

Skills: aws,kafka,mern stack,websocket,graphql,nginx