Backend Engineer – Python, FastAPI, Agentic AI & LLM

LetzBizz; Chennai District; On-site; INR 1,500,000 - 2,100,000; Full time

Job summary

LetzBizz is seeking a Backend Engineer to design and implement scalable backend services for an enterprise SaaS product powered by agentic AI and LLMs. You will build APIs, data services, and AI integrations, ensuring reliable operation at scale from the office in Chennai.

The role emphasizes strong Python development with FastAPI, PostgreSQL and Redis, plus experience with Docker, cloud platforms, and multi-tenant architectures. Immediate joiners preferred for a hands-on, collaborative team.

Qualifications

• 5–7 years of backend development experience.
• Strong Python backend development experience using FastAPI, Django or Flask in production.
• Strong knowledge of PostgreSQL and MongoDB, including schema design, query optimisation and migrations.
• Hands-on experience with Redis for caching, queuing or pub/sub.
• Production experience with LLMs or AI APIs, including prompt engineering, structured outputs and error handling.
• Experience with agentic AI patterns, RAG or AI orchestration frameworks.
• Strong understanding of event-driven and asynchronous architectures, message queues, background workers and task-processing frameworks.
• Hands-on experience with Docker and AWS or Azure cloud platforms.
• Experience working with multi-tenant systems, RBAC and tenant-scoped data management.
• Ability to write tested, maintainable code and proactively handle potential failure scenarios.

Responsibilities

• Design and develop scalable backend services, REST APIs and microservices.
• Integrate large language models and AI services into production workflows.
• Build agentic AI capabilities involving tool use, structured outputs, prompt management and multi-step orchestration.
• Develop integration adapters for enterprise systems, databases and third-party APIs.
• Implement asynchronous processing using background workers, schedulers, events and webhooks.
• Contribute to multi-tenant architecture, access control and tenant-level data isolation.
• Build observability, monitoring and reliability into backend services.
• Participate in system design discussions, code reviews and technical decision-making.

Skills

Python

FastAPI

REST APIs

PostgreSQL

MongoDB

Redis

Docker

Git

CI/CD

Agentic AI

LLMs

Prompt engineering

RBAC

Multi-tenant

Cloud (AWS/Azure)

Asynchronous architectures

Tools

Git

CI/CD

Pydantic

Job description

Backend Engineer – Python, FastAPI, Agentic AI & LLM

Job Title: Backend Engineer

Experience: 5–7 Years

Location: Guindy / OMR, Chennai

Work Mode: Work from Office – 5 Days a Week

Joining Preference: Immediate Joiners Preferred

About The Role

We are hiring an experienced Backend Engineer to build an enterprise SaaS product powered by agentic AI and large language models.

You will design and develop the backend services behind the product, including APIs, data services, AI integrations and the infrastructure required to operate the platform reliably at scale.

Key Responsibilities

• Design and develop scalable backend services, REST APIs and microservices.
• Integrate large language models and AI services into production workflows.
• Build agentic AI capabilities involving tool use, structured outputs, prompt management and multi-step orchestration.
• Develop integration adapters for enterprise systems, databases and third-party APIs.
• Implement asynchronous processing using background workers, schedulers, events and webhooks.
• Contribute to multi-tenant architecture, access control and tenant-level data isolation.
• Build observability, monitoring and reliability into backend services.
• Participate in system design discussions, code reviews and technical decision-making.

Technical Stack

Python

• FastAPI
• PostgreSQL
• MongoDB
• Redis
• Docker
• Pydantic
• MinIO/S3
• LLM APIs
• Git
• CI/CD

Required Experience And Skills

• 5–7 years of relevant backend development experience.
• Strong Python backend development experience using FastAPI, Django or Flask in production.Experience developing and scaling REST APIs and microservices used by real users.
• Strong knowledge of PostgreSQL and MongoDB, including schema design, query optimisation and migrations.
• Hands-on experience with Redis for caching, queuing or pub/sub.
• Production experience with LLMs or AI APIs, including prompt engineering, structured outputs and error handling.
• Experience with agentic AI patterns, RAG or AI orchestration frameworks.
• Strong understanding of event-driven and asynchronous architectures, message queues, background workers and task-processing frameworks.
• Hands-on experience with Docker and AWS or Azure cloud platforms.
• Experience working with multi-tenant systems, RBAC and tenant-scoped data management.
• Ability to write tested, maintainable code and proactively handle potential failure scenarios.

Why Join

This is an opportunity to join an early-stage enterprise product with a long-term roadmap. You will have meaningful ownership from the beginning and the opportunity to grow into architecture and technical leadership responsibilities as the engineering team expands.