Sagar Vadnere

Generative AI & Agentic AI | Full Stack Engineering

Sagar Vadnere Profile

Bio

AI & Full Stack Engineering Leader with 10.1+ years of experience architecting production-grade AI systems, scalable web platforms, and enterprise applications. Specializing in Generative AI, Agentic AI, LangGraph, LangChain, Hybrid RAG, LLM orchestration, AI evaluation, guardrails, React, Next.js, Python, TypeScript, AWS, and cloud-native engineering. Proven engineering leader managing a 10-member team and architecting platforms serving 1.2M+ monthly users across 8 countries.

Experience

Lead AI & Full Stack Engineer

Cognizant | Mar 2024 - Present

  • Leading a 10-engineer team in delivering production-grade AI solutions and multi-country digital platforms serving 1.2M monthly users across 8 countries, owning architecture, engineering standards, and cross-functional delivery.
  • Architecting a Salesforce Email-to-Case AI agent using LangGraph Plan-Execute-Validate-Synthesize workflows, Pydantic structured outputs, deterministic guardrails, and human-in-the-loop routing to extract and validate 8 business-critical case attributes.
  • Implementing hybrid RAG architecture on PostgreSQL/pgvector with multilingual embeddings, vector/fuzzy retrieval, CatBoost classification, lookup rules, reranking, and AWS Bedrock vision-language enrichment.
  • Orchestrating event-driven AI workflows across Confluent Kafka, Salesforce REST/Apex, OCR, and Azure Entra ID, incorporating resilient retries, dead-letter handling, attachment processing, and bidirectional case synchronization.
  • Establishing production-grade AI observability using Langfuse, LLM-as-a-Judge, ground-truth evaluation, confidence/abstention metrics, Datadog APM, and PostgreSQL-based quality dashboards.
  • Productionizing AI services using FastAPI, Docker, AWS EKS/ECR/Bedrock/SSM, Helm, Argo CD, Istio, IRSA, and GitHub Actions, while delivering a Next.js 14 BFF for review, validation, evaluation, and reference-data workflows.
  • Building natural-language self-service AI workflows enabling non-technical teams to generate country websites and manage URL redirects, reducing engineering dependency across content and launch operations.

Senior Web Developer

NP Digital | Sep 2021 - Mar 2024

  • Spearheaded modernization of a high-traffic PHP/Laravel monolith (800K monthly visits) into a decoupled React and Next.js SSR/SSG architecture, improving SEO, scalability, and rendering efficiency with zero production downtime.
  • Improved LCP from 3.8s to 1.4s and Lighthouse performance score from 48 to 92 through the React and Next.js migration.
  • Reduced server load by 30% via server-side rendering (SSR) and static site generation (SSG), cutting monthly infrastructure costs by ~$2,400.
  • Mentored 5 junior developers through structured code reviews, raising overall team code quality.
  • Partnered with product and design to deliver a modernized platform on schedule, improving accessibility and responsiveness with Material UI and modern CSS.

Software Developer

Hummingbird Web Solutions | Jul 2016 - Sep 2021

  • Led development of a B2C e-commerce platform processing 1,200+ orders/day, improving conversion through optimized checkout and responsive design; sustained 5x baseline traffic during peak sale events with zero downtime.
  • Engineered a secure multi-vendor marketplace with role-based access control, seller dashboards, and integrated payment gateways — onboarding 40+ vendors in the first quarter.
  • Built reusable React component architecture and resolved real-time cart and inventory synchronization challenges.
  • Conducted technical training on modern JavaScript practices and component-driven design, strengthening team capability.

Technical Skills

Programming Languages

Python, TypeScript, JavaScript (ES6+)

AI Engineering & Agentic AI

LangGraph, LangChain, AWS Bedrock, Claude, Gemini, Agent Orchestration, Tool Calling, Structured Outputs, Guardrails, A2A Protocol, Multi-Provider LLM Fallback, MCP

RAG, ML & AI Quality

Hybrid RAG, PostgreSQL/pgvector, Multilingual Embeddings, Vector & Fuzzy Retrieval, CatBoost, Reranking, LLM-as-Judge, Ground-Truth Evaluation, Confidence & Abstention Metrics, Langfuse

Backend, Data & Integration

FastAPI, Pydantic, Node.js, GraphQL, REST APIs, PostgreSQL, MongoDB, Confluent Kafka, Salesforce APIs, Document OCR, Backend-for-Frontend (BFF)

Frontend Engineering

React, Next.js, React Query, Zustand, Redux, Material UI, Tailwind CSS, SSR/SSG, HTML, CSS, Jest, Playwright

Architecture & Platforms

System Design, Monorepos, Multi-Tenant Systems, Microservices, API Design, Headless CMS, AEM, Sitecore, Platform Modernization, Web Performance, Accessibility, E-commerce Platforms

Cloud, DevOps & Observability

AWS EKS, ECR, Bedrock, SSM, Docker, Kubernetes, Helm, Argo CD, Istio, IRSA, GitHub Actions, CI/CD, Datadog APM

GitHub Contributions

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