RajChhapariya
AI and data engineer in Bengaluru. I build retrieval and analytics systems that cite their sources and refuse when they can't, and the products around them. Resume Roaster and Truly are live.
Reciprocal rank fusion, k = 60score = Σ 1/(60 + rank)Doc C lands 4th, outside the top 3.
Resume Roaster
A resume scanner I built and deployed. The code implements spatial PDF parsing, a bullet rewriter that avoids repeating a verb, and ATS-safe export. Next.js, Supabase and the OpenAI API.
Open the live siteRead the case study
Screenshot shows the product's own sample resume, not a real user's.
A retriever that checks its own evidence before it answers.
On four unanswerable questions it hallucinated 0 times; the plain hybrid baseline did 4 times. On 24 answerable ones it scored 45.8% where the baseline scored 60.4%, refused wrongly 12.5% of them, and took 17.7 s a question against 1.86 s for a single pass.Agentic RAG Knowledge Assistant, open source, Python. Held-out results from the 32-question test set of a 40-question dataset (8 development, 32 held-out), frozen before later auditor fixes. The sample is small: 24 answerable, four unanswerable and four false-premise questions.
one question, two passes (summarised from the repository's DEMO.md)! auditor verdict INSUFFICIENT_RETRY· gap: REALM index refresh details missing↻ bounded retry 1 of 2, narrower query✓ verdict SUFFICIENT, answer cites [1] [2]
Truly
A social platform built around structured 60-minute video circles of eight people and one host. Seat capacity is checked atomically inside a database transaction. Next.js, Drizzle and PostgreSQL.
Also built
- JanDarshanOpen-source civic information platform for India, with a 3D parliament view and an interactive map.
- MandateStackB2B SaaS subscription recurring billing platform for Indian businesses with Razorpay API, UPI AutoPay mandate integration, and automated dunning/retry webhooks.
- VyaparStackStatutory GST compliance and invoicing web application with automated CGST/SGST/IGST calculation across 36 states/UTs, in-memory pdf-lib invoice generation, and Neon Serverless PostgreSQL.
- Namma Metro GuideAn unofficial Bengaluru Metro guide for Android that I built on my own and published on Google Play: route search with interchange details, fare estimates, station information, an interactive map, favourites, and offline use.
Writing
- Hybrid Retrieval Systems in Production: Combining BM25, Dense Embeddings, and Reciprocal Rank Fusion
- Deterministic Guardrails for LLM Agents: Restricting SQL and Pydantic Schemas without Open-Ended Code Execution
- In-Process Columnar OLAP with DuckDB: Architecture, Vectorized Execution, and Analytics Engineering