Senior Applied AI & AI Platform Engineer

Hi, I'm Purnendu Das

I design and deliver production-grade AI systems — enterprise RAG, multi-agent workflows, LLM gateways, evaluation frameworks, and cloud-native GenAI platforms.

My journey runs from building ETL pipelines on GCP, through data science and the GenAI lab at Cognizant, to architecting entire AI platforms at PwC and EPAM for Fortune 500 clients. Along the way I've published practical handbooks, built open-source tools, and helped a 15K+ professional audience learn to build AI systems the right way.

5+ Years Building Systems 20+ AI & Data Systems 8 Open Source Projects
Purnendu Das

Experience

  1. Senior GenAI Developer @ EPAM Systems

    Aug 2025 – Present

    Bengaluru, India · Remote

    • Architecting an enterprise-grade Hybrid RAG system on AWS (Bedrock, OpenSearch, Lambda) for a Tier-1 US Finance client
    • Orchestrating end-to-end Chat Engine lifecycles with sub-second inference latency
    • Implementing PEFT and LoRA fine-tuning strategies for LLaMA and Gemma models
    • Serving as a Certified Technical Interviewer (A3-Level), evaluating 50+ candidates
    • Recipient of the Delivery Head Award for innovation in high-complexity AI initiatives
  2. GenAI Associate 2 @ PwC

    Aug 2024 – Aug 2025

    Bengaluru, India · Hybrid

    • Architected high-concurrency Multi-Agent microservice ecosystem on AWS for healthcare platform (60% efficiency uplift)
    • Engineered enterprise-grade RAG pipelines for US Financial client (40% accuracy improvement)
    • Pioneered LLM-driven Risk Intelligence engine with 70% latency reduction
    • Optimized LLM orchestration via Chain Parallelism (68% inference time reduction)
    • Received 9 awards from Project Manager, Delivery Head, and Partner for GenAI innovation and delivery excellence
  3. Data Scientist @ Cognizant

    Sep 2022 – Aug 2024

    Kolkata, India · Hybrid

    • Spearheaded R&D in the Generative AI Lab, transitioning experimental AI features to production on AWS
    • Architected Multi-Model GenAI Workflows using LangChain, Azure OpenAI, and Gemini Pro
    • Built a Semantic Search Engine with Pinecone (35% accuracy uplift)
    • Established DevSecOps with 100% regulatory compliance across all AI models
    • Received 7 leadership awards including 'Rising Star' (Anula Award) and 'Code As One', plus a 5/5 annual rating (Top 1%)
  4. Data Engineer @ Tata Consultancy Services

    Mar 2021 – Sep 2022

    Kolkata, India

    • Engineered scalable Cloud-Native ETL on GCP for enterprise analytics
    • Overhauled Apache Airflow orchestration (40% cost reduction, 80% automation)
    • Developed serverless Python Cloud Functions for automated data validation
    • Built high-throughput pipelines with BigQuery, Dataflow, and SQL (99.9% uptime)
    • Integrated Docker, Jenkins, and Bitbucket for CI/CD excellence
  5. Full Stack Web Developer (Django) @ Oneness Tech Solutions

    Aug 2020 – Feb 2021

    Kolkata, India · Remote

    • Architected a Full-Stack Predictive Analytics Platform with Django and Python
    • Engineered RESTful APIs and responsive interfaces with Ajax/JavaScript
    • Achieved 65% increase in organic web traffic through SEO optimization
  6. Python Developer (Intern) @ CodeSpeedy Technology

    Apr 2019 – Jun 2019

    Baharampur, India

    • Engineered Real-Time Weather Analytics Application with REST API integrations
    • Developed automated document generation engine for internship certifications
    • Architected Multi-Threaded Communication Framework using Python socket programming

Skills & Expertise

Generative AI & LLM

Generative AI ArchitectureLarge Language Models (LLM)LangGraph & LangChainLLMOpsRetrieval-Augmented Generation (RAG)Vector Databases (Pinecone, OpenSearch)Prompt Engineering & GuardrailsMulti-Agent SystemsLLM Fine-tuning (PEFT/LoRA)Model Evaluation & Observability

Programming & Development

PythonFastAPIDjangoJavaScriptHTML5SQLNoSQLRESTful APIsC (Programming Language)Object-Oriented ProgrammingData Structures & AlgorithmsFull-Stack Development

Cloud & Infrastructure

Amazon Web Services (AWS)Google Cloud Platform (GCP)AWS BedrockAWS LambdaAWS SageMakerStep FunctionsVertex AIBigQueryDataflowApache AirflowDockerJenkinsCI/CD for AI

Data Science & ML

Machine LearningData AnalysisStatisticsData VisualizationNLP (Natural Language Processing)Scikit-learnPandasRecord LinkagePlotly & MatplotlibPower BI

Tools & Practices

GitHubJIRASoftware DevelopmentProject ManagementLinuxDevSecOps (Checkmarx, Sonar, Black Duck)Web Development

Awards & Recognition

Delivery Head Award

EPAM Systems · Feb 2026

Recognized for excellence in Generative AI innovation and delivery of high-impact AI solutions

9 Awards from Leadership

PwC · Nov 2024 – Aug 2025

Recognized nine times for outstanding contributions in GenAI innovation and delivery excellence

Rising Star - Best Newcomer (Anula Award)

Cognizant · Jan 2024

Annual award recognizing exceptional technical contributions and leadership within the AI division

Code As One Award

Cognizant · Jun 2023

Recognized for exceptional collaborative achievements

IRA Top Performer (All India)

TCS · Mar 2021

Selected among only 22 toppers across India in Initial Readiness Assessment

Certifications

Education

B.Tech, Computer Science and Engineering

Government College of Engineering and Textile Technology, Berhampore, West Bengal

2016 – 2020 · 8.15 / 10 CGPA