# Raj Chhapariya — AI / Data Engineer

> Personal portfolio, technical case studies, and engineering essays for Raj Chhapariya, an AI / Data Engineer based in Bengaluru, India.

AI / Data Engineer building reliable data and LLM systems. Hands-on experience designing deterministic data guardrails, in-process columnar analytics with DuckDB, and evaluating RAG pipelines for factual precision and citation recall. Supported by full-stack engineering capabilities in TypeScript, Next.js, and PostgreSQL.

## Core Pages
- [Homepage](https://rajchhapariya.space/): Overview of portfolio, featured case studies, skills, and engineering philosophy.
- [About & Philosophy](https://rajchhapariya.space/about): Detailed biography, background, technical skillset, and operating principles.
- [Projects & Case Studies](https://rajchhapariya.space/projects): Production engineering case studies and technical architectures.
- [Technical Essays & Blog](https://rajchhapariya.space/blog): In-depth research articles on RAG evaluation, SQL guardrails, DuckDB OLAP, and Next.js.
- [Resume & CV](https://rajchhapariya.space/resume): Professional experience, education, verified skills, and downloadable vector PDF.
- [Full LLM Context](https://rajchhapariya.space/llms-full.txt): Complete, unabbreviated context, project case study details, and technical essays.

## Featured Projects & Case Studies
- [Agentic RAG Knowledge Assistant](https://rajchhapariya.space/projects/agentic-rag-assistant): Autonomous RAG pipeline with query planning, evidence quality verification, source citations, reciprocal rank fusion (BM25 + vector, k=60), and 87 automated test cases (Aug 2026 – Present).
- [AI Data Analyst Agent](https://rajchhapariya.space/projects/ai-data-analyst): In-process DuckDB analytics agent with read-only SQL enforcement, claim verification against raw data, evaluated on 20 questions, and Streamlit UI (Aug 2026 – Present).
- [Resume Roaster](https://rajchhapariya.space/projects/resume-roaster): AI-powered resume critique, ATS score analysis, bullet rewriter, and cover letter generator built with Next.js, Supabase, and OpenAI API (Jul 2026 – Present).
- [Satta Darshan](https://rajchhapariya.space/projects/satta-darshan): Civic political intelligence directory tracking Indian parliamentarians and ministers with Next.js, MongoDB, and automated Puppeteer scrapers (Apr 2026 – Jul 2026).

## Supporting Applications & Verified Platforms
- [Truly](https://trulyapp.online/): Intentional human-facilitated social video platform for young urban Indians (ages 18–30) featuring structured 60-minute video circles, double-blind mutual matching (2-hour SLA), Panda CSS tokens, and Neon serverless PostgreSQL with pessimistic row locking (Apr 2026 – Present).
- [AI Detector (SlopTotal)]: Forensic multi-engine AI text detection ensemble (23 engines across neural classifiers, GPT-2 token likelihood, surprisal CV, and heuristics) benchmarked across N=136 corpora with ROC-AUC 0.978 on RTX 4060 GPU and 0.0% false positives on pre-1920 classics (Aug 2026).
- [Aarohana Trails](https://www.aarohanatrails.com/): Freelance client trekking and adventure travel platform with custom CMS, Prisma ORM, and Next.js (Aug 2026 – Sep 2026).
- [SubsSync]: B2B SaaS recurring billing platform for Indian businesses with Razorpay UPI AutoPay integration (Jul 2026).

## Technical Essays & Research
- [Hybrid Retrieval Systems in Production: Combining BM25, Dense Embeddings, and Reciprocal Rank Fusion](https://rajchhapariya.space/blog/hybrid-retrieval-bm25-dense-embeddings-rrf): Deep architectural dive into lexical search limitations, vector space blindspots, and the mechanics of Reciprocal Rank Fusion.
- [Deterministic Guardrails for SQL-Generating LLM Agents: From Natural Language to Verified AST Execution](https://rajchhapariya.space/blog/deterministic-guardrails-sql-pydantic-llm-agents): AST validation and Pydantic schema enforcement to prevent dangerous queries and schema hallucinations.
- [Why In-Process Columnar OLAP is Replacing Traditional Data Warehouses for Analytical Microservices](https://rajchhapariya.space/blog/in-process-columnar-olap-duckdb-architecture): Replacing heavyweight data warehouses with zero-copy vectorized execution and embedded DuckDB.
- [Next.js 16 App Router Architecture: Server Components, Streaming SSR, and Static Site Generation](https://rajchhapariya.space/blog/nextjs-16-app-router-server-components-ssr): React Server Component execution boundaries, serialization protocols, and runtime memory optimization.
- [Evaluating Hallucination and Citation Faithfulness in Retrieval-Augmented Generation](https://rajchhapariya.space/blog/evaluating-hallucination-citation-faithfulness-rag): Methodologies and automated Python evaluation suites for measuring precision, citation recall, and context grounding in RAG.

## Optional & External Links
- [GitHub Profile](https://github.com/Rajchhapariya): Open-source repositories and code implementations.
- [LinkedIn Profile](https://www.linkedin.com/in/raj-chhapariya-63aa86201/): Professional network and background.
- [X / Twitter](https://x.com/raj_chhapariya): Technical updates and software engineering posts.
- [Download Resume PDF](https://rajchhapariya.space/resume.pdf): ATS-optimized downloadable one-page resume vector PDF.
- [Sitemap XML](https://rajchhapariya.space/sitemap.xml): Search engine and crawler discovery sitemap.