Sanath Kumar J S
Lead Software Engineer
.NET Full-Stack · AI / RAG Systems
Professional Summary
Results-driven Lead Software Engineer with 12+ years of full-stack .NET expertise, specialising in scalable distributed systems, RESTful API architecture, and production-grade AI/RAG pipelines. Shipped two semantic search systems in production (pgvector, HuggingFace embeddings, Groq LLM) processing millions of records at 300–800 ms p95 latency. Proven engineering leader — led and mentored teams of 4–6 engineers, drove 60% → 90% on-time delivery, and collaborated directly with US-based stakeholders across e-commerce, market research, and healthcare domains. Microsoft Certified Solutions Developer.
Technical Skills
Languages
Frameworks
AI / ML
Databases
Cloud / DevOps
Architecture
Tools
Professional Experience
Lead Software Engineer / Tech Lead
Ingenio Inc.(Keen Platform)
US consumer marketplace for psychic, tarot, and life-coaching services with 10M+ registered users.
Semantic Advisor Search
C# · .NET 8 · pgvector · HuggingFace · Groq LLM · Azure- Architected and shipped a production RAG-based semantic search engine replacing keyword search; improved advisor match quality by ~40% and user engagement measurably.
- Designed a 3-signal weighted vector search (questions ×0.45, title ×0.30, body ×0.25) with HNSW indexing — p95 query latency 300–800 ms at scale on Supabase pgvector.
- Implemented confidence-gated answer generation (HIGH ≥ 0.62 / MEDIUM ≥ 0.52) using Groq llama-3.3-70b; added pre-flight prompt injection detection eliminating hallucinated responses in production.
Advisor Feedback Search
C# · .NET 8 · pgvector · Semantic Search · Azure- Built second production RAG pipeline performing semantic search over 100,000+ advisor reviews with incremental ingestion — sub-second retrieval.
- Reduced review surfacing time from minutes (manual browsing) to sub-second, directly improving advisor conversion rates.
JWT Authentication Migration
C# · .NET 8 · JWT · OAuth 2.0 · RBAC- Led platform-wide zero-downtime migration from session-based auth to JWT across all services serving 10M+ users.
- Eliminated session state from all API services — reduced server memory consumption by ~30%. Designed RBAC policies and token refresh strategy.
Third-Party Platform Integrations
C# · REST APIs · Zendesk · Zinrelo · Iterable · ContentStack- Engineered Zinrelo loyalty rewards, Iterable marketing campaigns, Zendesk support, and ContentStack CMS integrations; designed API gateway layer with Polly retry policies and circuit breakers.
Leadership & Delivery
- Led and mentored a team of 4–6 engineers; conducted architecture reviews, code reviews, and 1:1s. Drove sprint on-time delivery from ~60% → ~90% within two quarters.
- Collaborated directly with US-based product managers; reduced mid-sprint scope changes by 35% through upfront requirement validation.
Senior Software Engineer / Tech Lead
Euromonitor International(Passport Platform)
Global market intelligence SaaS platform serving 400+ Fortune 500 companies across 100+ country markets.
Data Pipeline & Analytics
C# · .NET · SQL Server · React · Azure- Led technical design for a data pipeline processing 5M+ data points; improved report generation speed by 60% through query optimisation and strategic caching.
- Architected a hybrid microservice / monolithic platform aligned with domain boundaries, enabling independent scaling of high-traffic analytics modules.
- Delivered features end-to-end: C# Web API backends, React SPAs, SQL Server stored procedures, and Azure-hosted deployments.
- Mentored 3 junior developers; established code review standards and xUnit testing culture — increased code coverage from ~20% to ~65%.
Software Engineer / Consultant
Capgemini India Pvt. Ltd.(CarePricer)
US healthcare patient bill estimation tool for revenue cycle management.
Patient Cost Estimation Platform
ASP.NET Web API · Angular · SQL Server- Built CarePricer patient cost estimation platform integrating payer contracts, historical charges, and patient benefits; served 50+ hospital client integrations and reduced billing inquiry resolution time by 45%.
- Developed RESTful APIs, complex insurance benefit calculation logic (EOB parsing across multiple payer formats), and Angular front-end components with real-time validation.
Junior Developer (Intern → Full-time)
Toyota Tsusho Network Integration(Toyota Protect)
Extended warranty and insurance-related services platform for Toyota vehicle owners.
Warranty & Insurance Platform
C# · ASP.NET · SQL Server- Developed platform features for vehicle warranty and insurance management; built SQL Server stored procedures and data access layers for policy management, claims processing, and customer records.
Notable Projects
Next.js 14 · .NET 8 · pgvector · Groq · HuggingFace · Supabase
- Full-stack AI interview assistant using multi-signal RAG (3 embeddings per chunk: body, title, AI-generated question variants). Deployed on $0/month stack: Vercel + Render.com + Supabase + Groq.
- Implemented prompt injection detection, voice I/O (Groq Whisper STT + Web Speech TTS), session analytics, and unanswered question tracking with prep dashboard.
Education
B.E. Computer Science
SDM Institute of Technology, Ujire, Karnataka · 2008 – 2012
Certifications
Microsoft Certified Solutions Developer (MCSD) · Microsoft
Publications
NoSQL/MongoDB for Beginners
Deploying Node.js to Microsoft Azure