Indexnine Technologies - Full Stack Developer - React.js/Node.js

About the role :

Own a frontend module and backend end to end its component architecture, state strategy, performance budget, accessibility and test suite along with the API contracts it depends on. Roughly 70% frontend and 30% backend in Node.js services. You will work independently, contribute to architectural decisions, mentor one engineer, carry on-call, and present your work directly to enterprise client stakeholders.

What you will do :

• Own the component architecture and state strategy of a frontend module, recording non obvious decisions.
• Own the module's performance budget (bundle size, render performance, Core Web Vitals) and accessibility to WCAG 2.2 AA measured, not assumed.
• Own the test strategy, including component, integration and end-to-end coverage.
• Negotiate and validate API contracts with backend engineers, and implement endpoints where the feature requires it.
• Debug production issues across the frontend and backend boundary and write the root cause analysis.
• Review pull requests, mentor one engineer, and present design and delivery risk to clients.

What we are looking for :

• 3+ years with React and TypeScript in production applications.
• Production Next.js rendering modes, data fetching, caching behaviour.
• Demonstrated ownership of component architecture and state strategy on a real module.
• Measured performance work (bundle analysis, code splitting, render optimisation) and practical accessibility experience.
• Ownership of an end-to-end test suite (Playwright or Cypress) alongside component and integration tests.
• Daily use of AI coding assistants (Cursor, Claude, GitHub Copilot or equivalent) - prompt and context engineering, spec-driven development, and the judgement to verify output and catch AI-introduced defects in review.
• Strong Git and code review discipline, and evidence of mentoring other engineers.
• Confident written and spoken English for direct client communication.

Also part of the role :

• Strong working knowledge of Node.js and TypeScript with NestJS or Express.
• REST API design - validation, versioning, error contracts; GraphQL where used.
• PostgreSQL or MongoDB schema design, query optimisation and indexing.
• Debugging across the service boundary, and reviewing AI-generated backend code.

Nice to have :

• Agentic AI frameworks (LangGraph, CrewAI, PydanticAI)
• OpenAI SDK
• MCP
• RAG and vector databases
• Design systems and Storybook
• Micro-frontends
• AWS