AI Builder & Engineer
Chinmoy Paul
An AI builder who takes a product from a rough idea to something deployed, and keeps it running.
Where I Have Worked
Nistula · Boutique villa hospitality · Goa, India
Three months owning the AI layer end to end — the guest-facing assistant, and the booking site behind it.
What I shipped
WhatsApp AI host
Built solo to a tagged v1.0.0: a seven-tool agentic Claude loop that quotes live prices, reads PMS bookings, dispatches staff jobs against per-kind SLAs and remembers each guest across stays. Seven deterministic guardrails then run after the model and before every send — so the assistant structurally cannot state a price no tool returned, or promise an action nobody performed.
1,813 tests · 17 blocker defects caught pre-merge · 62-item live PMS backlog drained, 0 errors
Direct-booking villa site
Replaced a brochure page that could not take a booking. It reads live availability and pricing from the eZee PMS behind one swappable adapter, takes Razorpay payment and writes the reservation back — with the server re-quoting every price so a value from the browser is never trusted, and idempotency keys on all writes.
15 PMS endpoints behind one adapter · a Zod schema each · every price re-quoted server-side
My Portfolio
Agentic systems, evaluation harnesses and the infrastructure around them. Each one was built against a written spec and sealed by an independent review.
Data Engineering · Quant
A backtester and live screener that replayed one trader's intraday NSE F&O strategy over ten years of minute data and proved, with a full audit trail, that it loses money. The whole repo exists to make an unwanted answer hard to disbelieve.
188,345 trades · 2,621 tests, 0 failures · 28 adversarial reviews
Agentic AI · Live
An AI civic agent that takes a complaint from a single photo to verified resolution — it files in the citizen's own language, tracks the statutory SLA, and autonomously drafts the escalation ladder up to an RTI when the deadline lapses.
Live on Cloud Run · 36 tests, green CI · Open311 export
Agentic AI · Production
A WhatsApp AI host for a Goa villa company — live-priced quotes, staff job dispatch with SLAs, and an automated guest lifecycle. The model writes; seven deterministic checks decide whether what it wrote may leave the building.
1,813 tests · 7 code-enforced guardrails · 0 model-invented prices
Infrastructure · Observability
An open-source LLM on a single-node cluster where the interesting problem isn't getting it to run — it's knowing continuously whether it's still producing tokens fast enough. Ollama exposes no metrics, so I built the exporter.
8 metric families · 11 Grafana panels · alerts that fired on real degradation
LLM Orchestration · Live
Bilingual EN/AR support triage where an LLM reads the complaint and a hand-written 36-cell policy table decides the entitlement. The classifier returns its own escalation verdict — and the engine deliberately ignores it.
88.5% on a 78-dimension eval rubric · 0 pipeline failures
Backend · API
One HTTP endpoint that collapses a customer's scattered emails and phone numbers into a single identity. Instead of walking a graph, it holds the link depth at exactly one and makes merges pay for it — union-find with eager path compression.
2 SELECTs per lookup, no matter how many merges
A direct-booking villa site wired live to the eZee PMS behind one swappable adapter, with Razorpay payment and server-side re-quoting on every write.
A seven-question funnel that scores every signup and ranks the operator's outreach list. Two questions score backwards on purpose — it measures unmet pain, not seniority.
Asks Gemini the questions a real buyer would type, then scores whether a brand survives into the answers — a surface conventional SEO tooling cannot see.
A crypto trading backend: users sign up, fund a wallet through Razorpay or Stripe, buy and sell at live CoinGecko prices, track a portfolio and withdraw to a bank. 37 endpoints across 14 entities, with JWT auth and email two-factor.
Three article URLs in, one email-client-safe HTML brief out. Two of its four scrapers hang off generated CSS hashes rather than stable hooks, and the README says which ones will break first.
What I Have Written
I write up the systems I build — including the parts that did not work.
Featured · Hashnode · Apr 2026
3,400 words on why a healthy pod tells you nothing about a working model — and the two-layer readiness split that fixed it.
Code · GitHub
Each project with its spec, decision log and review trail committed alongside the code.
