Subbusainath Rengasamy

Summary

Senior Software Engineer with 7+ years building scalable, cloud-native systems, specialising in AI-augmented engineering and production-grade backend architecture. Currently shipping AI-powered features across an end-to-end HR Tech platform — internal tools and customer-facing systems — using LLM-assisted development workflows. Deep expertise in distributed systems, serverless architecture, and multi-cloud environments (AWS, GCP, Azure). Owns systems end-to-end from design to production while leveraging AI tools to accelerate delivery, improve code quality, and drive engineering efficiency.

Core Skills

AI / GenAI

LLM APIs (Anthropic, OpenAI, Vertex AI, Bedrock) · AI-assisted development (Claude Code, Codex, OpenCode, Ollama) · Prompt engineering & evaluation · Agent workflows (LangGraph, AutoGen, CrewAI, n8n, Agentic Core) · Vertex AI Studio, SageMaker, Bedrock Agents · RAG, vector search (pgvector, OpenSearch, FAISS)

Backend & Fullstack

Python, Node.js, Go, TypeScript · FastAPI, Flask, Django, Express · REST, GraphQL, microservices, event-driven · React, Next.js, Astro

Cloud & Infrastructure

AWS, GCP, Azure · Serverless (Lambda, Cloud Run, Step Functions) · Terraform, AWS CDK, Pulumi · CI/CD, GitHub Actions, Harness

Data & Systems

PostgreSQL, MySQL, DynamoDB · OpenSearch, FAISS, pgvector · Kafka, Flink, EventBridge · PySpark, Databricks

DevOps & Observability

CloudWatch, New Relic, Lumigo · Prometheus, Grafana · MLflow, Argo Workflows · Docker, Kubernetes, Podman

Experience

1. Senior Software Engineer — Cloud & AI

   Berribot Private India Limited · Remote · India

   Mar 2025 — Apr 2026

   • Built and scaled AI-powered features for an end-to-end HR Tech platform, covering internal tools and customer-facing products.
   • Architected and shipped an AI Voice Proctoring system with MLOps pipelines — hybrid serverless ingest on Cloud Run with containerised GPU diarization (Pyannote) feeding a RAG pipeline on Vertex AI that emits PDF reports with timestamped, citation-grounded evidence.
   • Leveraged AI-assisted development tools and LLM-based workflows to accelerate feature delivery and improve engineering productivity across the team.
   • Owned end-to-end delivery from system design to production deployment, ensuring scalability and reliability.
   • Designed and deployed backend systems across AWS and GCP using serverless and distributed architecture patterns.
   • Acted as senior consultant for DevOps and system reliability, resolving critical production issues and lifting system performance.
   • Implemented enterprise-grade features such as Azure-based SSO integrations for customer-specific requirements.

2. Software Engineer / Senior Software Engineer

   CommentSold · Remote · USA

   Feb 2024 — Oct 2024

   • Contributed to backend systems for a high-traffic live commerce platform supporting real-time transactions and user interactions.
   • Designed and developed scalable microservices and APIs to power core product features with high availability.
   • Optimised system performance and reliability to absorb increasing user load and business growth.
   • Collaborated with product and cross-functional teams to deliver features aligned with business and user needs.
   • Resolved production incidents and improved system stability in a fast-paced product environment.

3. Senior Developer

   Redgrape Business Services · Remote

   Feb 2023 — Feb 2024

   • Led migration of legacy commerce systems (Oracle ATG → commercetools) into a scalable serverless architecture using AWS Lambda, Step Functions, and EventBridge — achieving ~65% cost reduction.
   • Built shared backend architecture using a Turborepo monorepo, AWS Lambda Layers, and reusable packages to lift developer productivity.
   • Optimised Lambda performance (10 MB → 287 KB bundles), significantly improving execution efficiency and reducing latency.
   • Mentored engineers on TypeScript, system design, and scalable backend development.

4. Member of Technical Staff 2

   Antstack Technologies Pvt Ltd · Bengaluru · India

   Dec 2020 — Jan 2023

   • Built scalable backend systems and data pipelines using AWS serverless and big-data technologies.
   • Developed pipelines processing 50M+ records with PySpark on Databricks, reducing manual effort by 75%.
   • Designed backend systems with Lambda, DynamoDB, API Gateway, and Cognito, cutting infrastructure cost by 45%.
   • Implemented OpenSearch-based search systems for real-time applications.

5. Associate Consultant 2

   Atos Syntel Private Limited · Chennai · India

   Nov 2018 — Nov 2020

   • Built enterprise backend systems with Node.js and AWS, improving performance and reliability.
   • Contributed to a microservices architecture that increased scalability and redundancy.
   • Lifted application performance from 67% to 78% through backend optimisations.