Leo Varghese — Resume

Summary

Software engineer with 4+ years building production systems in Python and Django. Currently embedded at Thomson Reuters via SII India, working on search infrastructure — OpenSearch migrations, bias detection with LLMs, and infrastructure cost reduction. Comfortable owning work end-to-end across the full lifecycle: design, implementation, deployment, and measurement. Strong on AWS, distributed systems, and LLM integration.

Experience

Software Engineer Jan 2025 – Present

SII India · Embedded at Thomson Reuters

Built an in-house bias detection filter for OpenSearch results, replacing a paid vendor (Coactive). Achieved 94% accuracy with a 2-second AWS Lambda response time using Python, LangChain, and Serverless Framework.
Migrated OpenSearch cluster from x86 to ARM after benchmarking both architectures on the real workload — saving $11,000/year in infrastructure costs.
Built reusable Claude skills for prompt iteration and model migration workflows, adopted by the engineering team.

Backend Engineer 2021 – Jan 2025

Impress.ai

Owned end-to-end integration of 7+ enterprise assessment platforms (SHL, Aon, Aon Gate, Pulsify, HackerRank, HackerEarth) into a production hiring system processing thousands of candidates per day for DBS Bank.
Built a client-facing analytics dashboard with modular architecture, real-time data, and per-client customisation using Django, DRF, and Django Channels.
Built an internal test platform enabling the ops team to self-serve integration verification, eliminating routine engineering toil.
Integrated internal ticketing with Freshdesk for cross-platform support sync.

Skills

Languages Python, Django, Django REST Framework, Celery, Django Channels Cloud AWS (Lambda, ECS, CloudFormation, S3), DigitalOcean Search OpenSearch (migration, performance tuning, vector search) AI / LLM LangChain, LLM/SLM integration, Claude API Infra Docker, GitHub Actions, Jenkins, Serverless Framework Databases PostgreSQL, Redis, SQLite3 Observability Sentry, Grafana, Kibana, Loki APIs REST, SOAP, GraphQL

Selected Projects

Bias Detection Filter — Thomson Reuters (via SII India)

Python · LangChain · AWS Lambda · Serverless Framework · GraphQL · OpenSearch

In-house alternative to a paid bias-detection vendor. Matched commercial accuracy (94%) at a fraction of the cost. Lambda response under 2 seconds.

ARM Migration + OpenSearch Optimisation — Thomson Reuters (via SII India)

AWS ECS · OpenSearch · CloudFormation · GitHub Actions · Python

Benchmarked x86 vs ARM on actual production workload; migrated cluster to ARM saving $11k/year. Fixed a 7 GB memory footprint issue. Migrated CI/CD from Jenkins to GitHub Actions.

Enterprise Assessment Integrations — Impress.ai / DBS Bank

Python · Django · DRF · Celery · REST · SOAP · PostgreSQL · Redis

Sole owner of 7+ vendor integrations into a hiring platform processing thousands of candidates daily. Delivered analytics dashboard and internal self-serve test tooling.

Internship

Software Developer Intern Summer 2015

Gxtron Innovations · Mookannur, Kerala

Helped develop UI for a mirror system using PyQt and HTML.
Built an interface to save user data in Firestore using Python and Firebase SDK.

Courses & Training

Apr 2026 Generative AI: Working with Large Language Models — LinkedIn Learning 2023 AWS Cloud Technical Essentials — Coursera 2020 Front-End Web Development with React — Coursera 2019 Python for Data Science — NPTEL 2019 HTML5 & CSS3 Fundamentals — Microsoft Virtual Academy