Open to opportunities

Justin Joy

@justinjoy

Message

I build production Python backends and GenAI systems with reliable evaluation and guardrails.

India

Message

What I'm looking for

I'm looking to build production AI and backend platforms end to end, with ownership of architecture, delivery, evaluation, safety, and scalable cloud infrastructure.

At Datafortune, I rebuilt a US ed-tech GenAI backend from scratch, delivering LangGraph workflows, multi-provider LLM orchestration, automated evaluation, and safety guardrails. I reduced failed generation profiles from 30% to 6.7%, improved runtime by approximately 25%, and helped produce 40,000+ questions.

Previously, I built Lighthouse for JioMart at Fynd, handling approximately 2 million API requests during flash sales, and owned five FastAPI and Sanic catalog microservices. Across Python, Go, AWS, Kafka, and MongoDB, I build production systems end to end, lead client-facing delivery, and mentor engineers.

Experience

Work history, roles, and key accomplishments

Current

Senior Software Engineer (Python, Applied AI)

Current

Datafortune

Apr 2025 - Present (1 year 4 months)

Rebuilt a US ed-tech GenAI backend from scratch, designing a production LangGraph pipeline and multi-provider LLM layer. Reduced failed generation profiles from 30% to 6.7% and improved runtime by approximately 25%.

Python LangGraph Claude Gemini OpenAI fastAPI Kafka AWS Docker Prompt Caching LLM As Judge RAG MongoDB Redis

Software Development Engineer II (Python)

Fynd

Oct 2022 - Mar 2025 (2 years 5 months)

Led development of Lighthouse for JioMart, managing approximately 2 million API requests during flash sales. Owned five catalog microservices and delivered Doorstep Quality Check end-to-end on a one-week deadline.

Python fastAPI Sanic Kafka Pandas Microservices REST APIs AWS Docker Kubernetes GitHub Actions CI CD

Python Developer

Route Mobile Limited

Feb 2021 - Sep 2022 (1 year 7 months)

Developed production REST APIs and concurrent services using Flask and FastAPI within a microservice architecture. Implemented asynchronous background processing with Celery and RabbitMQ.

Python Flask fastAPI Celery RabbitMQ Microservices REST APIs S3 Cloudwatch Linux

Software Developer

Qtech Software

Jan 2018 - Oct 2020 (2 years 9 months)

Developed Flask and Flask-RESTful services and automated data collection and processing workflows using Python, Pandas, and Selenium. Built room and hotel mapping capabilities using machine learning and NLP.

Python Flask Pandas Selenium Machine Learning NLP Go