Senior MERN Stack Developer

We are a fast-growing SaaS company building a scalable web platform used by thousands of daily active users. We're looking for a battle-tested Senior MERN Stack Developer to lead feature development, improve system architecture, and mentor junior developers. You will own end-to-end delivery — from database modeling to polished React UIs — and collaborate directly with our product and design teams. This is a high-impact role where you'll work on real-time data, third-party integrations, and complex user workflows. We ship fast, iterate often, and take code quality seriously. RESPONSIBILITIES - Design and implement full-stack features using MongoDB, Express.js, React, and Node.js - Architect scalable REST APIs and integrate third-party services (payment gateways, OAuth providers, etc.) - Write clean, testable, and well-documented code following industry best practices - Optimize frontend performance (lazy loading, code splitting, memoization) - Manage database schemas, indexing strategies, and query optimization in MongoDB - Participate in code reviews, sprint planning, and async stand-ups - Identify technical debt and proactively propose solutions - Mentor mid-level developers and contribute to internal documentation REQUIRED SKILLS (What will make you WIN this job) 1. Advanced React & State Management - Deep knowledge of hooks, Context API, Redux Toolkit or Zustand - Ability to architect large-scale SPAs and reusable component libraries 2. Node.js & Express.js API Development - Production-level experience building secure, scalable REST or GraphQL APIs - Middleware design, JWT/OAuth authentication, and proper error handling 3. MongoDB & Database Architecture - Schema design, aggregation pipelines, indexing strategies, Mongoose ORM - Experience with MongoDB Atlas and query performance tuning 4. DevOps & Deployment Pipelines - Hands-on with Docker, CI/CD (GitHub Actions or CircleCI) - Deploying to AWS, GCP, Vercel, or Railway — comfortable with env configs and secrets management 5. Security & Performance Optimization - OWASP best practices, rate limiting, input validation, XSS/CSRF prevention - Profiling and optimizing Node.js apps under production load 6. Agile Collaboration & Git Workflow - Strong async communication, disciplined Git practices (feature branches, PRs, semantic commits) - Experience working in remote-first, agile/scrum teams 7. Testing & Code Quality - Unit, integration, and E2E tests using Jest, React Testing Library, Supertest, or Cypress - You treat tests as a first-class deliverable, not an afterthought REQUIREMENTS - 5+ years of professional software development experience - 3+ years of focused MERN stack development in production environments - Proven track record of delivering full-stack features independently - Strong English communication skills (written and spoken) - Available for at least 4 hours of overlap with UTC+0 to UTC+5 - Portfolio or GitHub profile with relevant professional or open-source projects NICE TO HAVE - Experience with microservices or event-driven architecture - Familiarity with GraphQL (Apollo Server/Client) - Prior work on SaaS or B2B platforms - Upwork Top Rated or Top Rated Plus badge HOW TO APPLY (Read carefully) To be considered, start your proposal with the word "MERN" — this tells us you read the full post. Generic copy-paste proposals will be ignored. Then briefly answer the following: 1. Describe a complex full-stack feature you built end-to-end (what was the problem, what did you build, and what was the outcome?) 2. What is the most challenging technical problem you've solved with Node.js or MongoDB? 3. Share your GitHub profile or portfolio link (or a short Loom walkthrough of relevant work) 4. What is your timezone and available working hours? 5. Can you join a 30-minute video call within 48 hours of applying? We value long-term relationships. Top performers will be offered expanded scope and higher rates over time. We look forward to hearing from you!