Full Stack Developer -MERN

Xcelore; Dadri; On-site; INR 1,200,000 - 2,400,000; Full time

Job summary

Xcelore in India is seeking a skilled full-stack developer to build and ship production web apps end to end. You will work with React, Next.js on the frontend and Node.js/NestJS on the backend with MongoDB, crafting APIs, integrating AI features, and owning deployment pipelines.

You will collaborate with product/design teams to scope, estimate features, and ship them in sprints, ensuring performance, security, and quality across the stack.

Qualifications

• Bachelor's degree or equivalent practical experience.
• 3–5 years of full-stack JavaScript/TypeScript experience.
• Strong TypeScript and modern JavaScript (ES6+).
• Production experience with React and Next.js (App Router, data fetching, caching).
• Production experience with Node.js and NestJS, or Express with NestJS architecture.
• MongoDB design, indexing, and aggregation pipelines; SQL/PostgreSQL a plus.
• Hands-on CI/CD experience (GitHub Actions, GitLab CI, Jenkins).
• Working knowledge of Docker and cloud deployment (AWS/Azure/GCP).
• Experience writing unit, integration, and end-to-end tests (Jest, Cypress, Playwright).
• Familiarity with state management and build tooling (Redux Toolkit, React Query).
• Comfort debugging across stack from browser to database.

Responsibilities

• Build and ship full-stack applications using React, Next.js, Node.js, NestJS, and MongoDB.
• Design REST APIs and GraphQL with clear contracts, validation, and versioning.
• Develop modular NestJS backends with DI, guards, interceptors, and DTOs.
• Leverage Next.js rendering strategies for performance and SEO.
• Integrate LLM APIs for AI features, including RAG and embeddings.
• Own CI/CD pipelines, containerized releases, and environment management.
• Profile and optimize slow queries, APIs, and bundle sizes.
• Apply security basics: JWT/OAuth, input validation, rate limiting, OWASP awareness.
• Review code, write tests, and document decisions.
• Collaborate with designers/product managers to scope and deliver in sprints.

Skills

React.js

Next.js

Node.js

NestJS

JavaScript

TypeScript

MongoDB

REST API

GraphQL

PostgreSQL

AWS / Azure / GCP

Docker

CI/CD

Git / GitHub

Jest / Cypress / Playwright

Redux Toolkit / React Query

Microservices

Education

Bachelor's degree in Computer Science, Engineering, or related field

Tools

Docker

Kubernetes

GitHub Actions

GitLab CI

Jenkins

Job description

THE ROLE

You will build and ship production web applications end to end: React and Next.js on the front, Node.js and NestJS on the back, MongoDB underneath. You will work directly with product and design, own features from API design to deployment, and add AI-powered capabilities (LLM integrations, retrieval, automation) to the products we build for clients.

WHAT YOU'LL DO

• Build and maintain full-stack applications with React, Next.js, Node.js, NestJS, and MongoDB.
• Design REST APIs, and GraphQL where it fits, with clear contracts, validation, and versioning.
• Build modular, testable NestJS backends using dependency injection, guards, interceptors, and DTOs.
• Use Next.js rendering strategies (SSR, SSG, ISR, server components) to hit performance and SEO targets.
• Integrate LLM APIs (OpenAI, Anthropic, or open-source models) into product features: prompt design, streaming responses, RAG pipelines, and embeddings with a vector store.
• Own CI/CD for your services: build, test, and deploy pipelines, containerized releases, and environment management.
• Profile and optimize slow queries, API response times, and bundle sizes.
• Apply security basics in every feature: authentication and authorization (JWT, OAuth), input validation, rate limiting, secrets management, and OWASP Top 10 awareness.
• Review code, write tests, and document your decisions.
• Work with designers and product managers to scope, estimate, and ship features in sprints.

WHAT YOU NEED

• Bachelor's degree in Computer Science, Engineering, or a related field (or equivalent practical experience).
• 3 to 5 years of professional experience building full-stack JavaScript/TypeScript applications.
• Strong TypeScript and modern JavaScript (ES6+).
• Production experience with React and Next.js (App Router, data fetching, caching).
• Production experience with Node.js and NestJS, or Express with a clear understanding of NestJS architecture.
• MongoDB experience: schema design, indexing, aggregation pipelines. Working knowledge of SQL/PostgreSQL is a plus.
• Hands-on experience with CI/CD (GitHub Actions, GitLab CI, or Jenkins) and Git workflows.
• Working knowledge of Docker and deploying to a cloud platform (AWS, Azure, or GCP).
• Experience writing unit, integration, and end-to-end tests (Jest, Supertest, Playwright, or Cypress).
• Familiarity with state management and build tooling (Redux Toolkit, React Query, Vite, Turbopack).
• Comfort debugging across the stack, from browser to database.

GOOD TO HAVE

• Experience building AI features: LLM API integration, RAG, vector databases (Pinecone, pgvector, Qdrant), or agent frameworks (LangChain, LlamaIndex).
• Kubernetes, Terraform, or other infrastructure-as-code experience.
• Redis, message queues (RabbitMQ, Kafka, BullMQ), or WebSockets.
• Monitoring and observability (Sentry, Grafana, Datadog, OpenTelemetry).
• Experience with microservices or monorepos (Nx, Turborepo).
• Agile/Scrum experience in a client-facing environment.

Key skills

• React.js
• Next.js
• Node.js
• NestJS
• JavaScript (ES6+)
• TypeScript
• MongoDB
• REST API
• GraphQL
• PostgreSQL
• AWS / Azure / GCP
• Docker
• CI/CD
• Git / GitHub
• Jest / Cypress / Playwright
• Redux Toolkit / React Query
• Microservices