Senior Full Stack Developer (Node.js / NestJS / Next.js / AI)

Company : CodeQuery (Querycode Techno Private Limited) Location : Patna, Bihar (with projects spanning our Perth, Australia operations) Experience : 2-5+ years (skill matters more than years) Employment Type : Full-time

About the Role

CodeQuery builds full-stack white-label SaaS platforms for home and field service businesses (the SerQ platform), alongside custom software, digital marketing, and agency services for clients across India and Australia.

We're looking for a Senior Full Stack Developer who can independently design, build, and ship production-grade systems—and who's excited to help us push our backend stack from Express toward NestJS as we scale SerQ's multi-tenant, white-label architecture. You'll own features end-to-end, from architecture through deployment, without needing every ticket fully spec'd out for you.

What You'll Build

- Multi-tenant, white-label SaaS modules for the SerQ platform
- AI-powered tools and internal automation
- REST APIs and backend services migrating to NestJS
- Client-facing platforms across home services, healthcare, salon/spa, and field service verticals
- Payment, maps, and messaging integrations
- Production deployment pipelines

Core Requirements

JavaScript & TypeScript

- Strong grasp of JavaScript fundamentals: closures, async/await, the event loop, prototypes—enough to debug real production issues
- TypeScript fluency is required (not optional). NestJS only pays off if you actually think in types.

Backend - NestJS First





We're standardizing new services on NestJS. If you haven't used it before but have solid OOP/dependency injection instincts (e.g., from Spring or Angular), we'll consider you and expect a fast ramp-up.

- NestJS: modules, providers, dependency injection, guards, interceptors, pipes
- Solid understanding of OOP, SOLID principles, Clean Architecture, Repository Pattern
- REST API design, JWT/OAuth, middleware, queues, cron jobs
- Comfortable reading and refactoring legacy Express code into NestJS modules. This is a real near-term task, not a hypothetical.

Frontend

- React.js
- Next.js (App Router, SSR/ISR)

Database

- MongoDB or PostgreSQL as a primary database (schema design, indexing, query optimization)
- Basic Redis for caching and sessions

Git & Workflow

- Real team Git experience: branching, pull requests, rebase, and conflict resolution

Deployment

AI Integration

Practical experience calling LLM APIs (OpenAI, Gemini), building agent or tool-calling workflows, and working with structured outputs—not just casual ChatGPT use.

Integration Experience

Experience with any 2-3 of the following (not all required):

- Payment gateways: Razorpay, Cashfree, or Stripe




- Cloud storage: AWS S3 or equivalent
- Maps and location APIs
- Firebase (Authentication, FCM)
- WhatsApp Business API

Nice to Have

- Docker
- Prisma or Drizzle ORM
- Prior experience with multi-tenant SaaS, booking systems, CRM, or field-service platforms
- GraphQL
- WebSockets

Responsibilities :

- Design and build NestJS-based backend services, including migrating select legacy Express modules
- Develop reusable, performant frontend components in Next.js
- Design and optimize database schemas across client verticals
- Integrate third-party APIs (payments, maps, messaging, cloud storage)
- Build and maintain AI-powered workflows and automations
- Write clean, documented, and testable code while participating in code reviews
- Collaborate directly with founders, designers, and QA in a small, fast-moving team

What We're Evaluating

- A GitHub profile with real, non-tutorial projects
- Ability to explain technical decisions you made and the reasoning behind them—not just list technologies

How to Apply

- Node.js, NestJS, TypeScript
- Next.js, React.js
- MongoDB or PostgreSQL, Redis
- Any of: Razorpay, Cashfree, AWS S3, Google Maps API, WhatsApp Business API, Firebase
- Git & GitHub workflow
- Linux, Nginx, PM2 deployment experience
- AI agent / LLM API integration experience

Pay: ₹22,000.00 - ₹35,000.00 per month

Benefits :

- Flexible schedule
- Paid sick time
- Paid time off

Work Location: In person

📌 Senior Full Stack Developer (Node.js / Nestjs / Next.js / Ai) (Patna)
🏢 Codequery
📍 Patna