Open to opportunities

Sanjay Kumar

@sanjaykumar17

Message

Backend Developer and Python full-stack engineer building scalable REST APIs and GenAI RAG systems.

India

Message

What I'm looking for

I’m seeking to contribute backend engineering expertise to drive business impact—building secure, scalable FastAPI/Django REST APIs and production GenAI (RAG) systems—at a forward-thinking organization that values performance, quality, and real outcomes.

I’m a results-driven Python Backend heavy Full stack Developer with 4+ years of experience building scalable, secure backend applications and REST APIs. I also code in React.js, and I bring deep DSA knowledge alongside production-grade API engineering.

At Tata Consultancy Services, I architected and developed high-availability REST APIs for enterprise clients like Visa Inc. and BT Group—using FastAPI and Django REST Framework to improve performance, security, and reliability. I’ve implemented JWT-based authentication with OAuth2 standards, enforced request validation with Pydantic, and generated OpenAPI-compliant documentation (Swagger UI and ReDoc) for fast integration.

I’m particularly excited by GenAI engineering: I’ve delivered production-style multi-tenant SaaS and built RAG systems using OpenAI APIs and retrieval pipelines (including hybrid vector + BM25 reranking). I also maintain strong engineering fundamentals—ORM query optimization, extensive unit/integration testing (90%+ coverage), and I’ve received an On-the-Spot Award for outstanding project contribution.

Experience

Work history, roles, and key accomplishments

Current

Backend Developer - Visa

Current

Tata Consultancy Services Ltd.

Jul 2025 - Present (11 months)

Architected and developed scalable, high-availability FastAPI REST APIs and generated OpenAPI (Swagger UI/ReDoc) documentation for enterprise services. Implemented secure JWT-based authentication/authorization using OAuth2 standards with Pydantic request validation, and used GitHub Copilot/Claude Code to accelerate development.

fastAPI REST APIs JWT OAUTH2 Pydantic OpenAPI Authorization GitHub Co Pilot Claude Code

Backend Developer - BT

Tata Consultancy Services Ltd.

Jun 2022 - Jul 2025 (3 years 1 month)

Architected scalable, high-availability Django REST Framework APIs and implemented JWT-based authentication to secure protected endpoints. Optimized Django ORM queries to reach a 90% API responsiveness rate, maintained 90%+ code coverage with unit/integration testing, and produced Swagger UI docs via DRF Spectacular.

Django Django REST Framework DRF JWT Django ORM Optimization Unit Testing Integration Testing Agile Collaboration

Education

Degrees, certifications, and relevant coursework

Gokaraju Rangaraju Institute of Engineering and Technology

Bachelor of Technology, Electronics and Communication Engineering

Grade: CGPA: 9.12/10; Top 5 of the class

Earned a B.Tech in Electronics and Communication Engineering at Gokaraju Rangaraju Institute of Engineering and Technology, graduating in June 2022 with a CGPA of 9.12/10 and ranking in the top 5 of the class.