Backend Engineer

Node.js, APIs & Production Services

Mumbai (On-site) | Full-time | 3-5 years

Unico Connect is an AI-first technology partner that builds custom mobile, web, and AI products for clients across multiple geographies. We are hiring a Backend Engineer who will build production-grade backend services across customer engagements, partnering closely with senior backend engineers, frontend engineers, AI engineers, and DevOps.

The mandatory requirement for this role is hands-on production experience shipping Node.js services, with ownership of at least one feature area end to end including API design, data modelling, and testing. The role is hands-on. Expect to implement APIs, design schemas, work with queues and caches, integrate with AI services, write tests, and review the work of others. A typical week includes a feature implementation, a database migration review, a working session with a frontend engineer on an API contract, and a code review with peers.

• API and service development: Build REST and GraphQL APIs in Node.js (Express, NestJS, Fastify) with TypeScript. Cover authentication, validation, error handling, and structured logging.
• Database design and queries: Design PostgreSQL schemas, write efficient queries, and own migrations for the feature areas you ship.
• Caching and background work: Implement caching with Redis and background workers using BullMQ, RabbitMQ, or SQS for asynchronous workflows.
• AI service integration: Integrate backend services with internal and third-party AI APIs. Handle streaming responses, retries, structured outputs, and failure modes.
• Testing: Write unit, integration, and contract tests. Build the discipline of automated testing into every feature.
• Observability and security basics: Instrument services with structured logging, metrics, and tracing. Apply secure-by-default practices including input validation, authorisation, secret handling, and dependency hygiene.
• AI-assisted development: Use Claude, Cursor, and similar tools day to day. Build discipline for reviewing and validating AI-generated code.

• Hands-on production Node.js experience (mandatory). Must have personally shipped at least one feature area end to end in a production Node.js service, owning API design, data modelling, and testing. POCs and internal tools alone do not qualify.
• 3 to 5 years of professional backend engineering experience.
• Strong Node.js and TypeScript. Production work with Express, NestJS, or Fastify. Comfort with async patterns and error handling.
• Python as a plus. Hands-on experience with FastAPI, Django, or Flask is a meaningful advantage. Willingness to pick up Python as engagements demand is required.
• PostgreSQL. Schema design, indexing, query optimisation, and migrations on at least one production system.
• Redis and queues. Hands-on with Redis for caching and at least one queue system (BullMQ, RabbitMQ, SQS).
• AWS familiarity. Working knowledge of EC2, S3, IAM, and RDS. Comfort with Docker and basic deployment workflows.
• Testing fluency. Unit, integration, and at least one of contract or end-to-end testing.
• Strong written and spoken English communication.

Nice to have: GraphQL (Apollo); event-driven architectures (Kafka, NATS); workflow orchestration exposure; AI service integration experience; OpenTelemetry instrumentation.