# Samrat Mukherjee — experience

> Professional roles in full. AI Engineer · AI Agent Developer.

## Professional experience

### AI Engineer & Founder — Shortlistapp.co (Remote)

Jan 2026 – Present

Live AI agent product with paying customers. The agent applies to jobs end to end — it reads the posting, fills the application, answers the employer's open-ended questions from the user's real background, and submits.

- Built an autonomous job-application agent in Python (FastAPI, LangGraph) that plans and executes a full application as a stateful multi-step workflow, resolving each field through tool calls, recovering cleanly on step failure, and escalating to the user when it cannot proceed safely.
- Built a RAG pipeline over each user's resume and history (embeddings + Pinecone) so open-ended employer questions are answered from the user's actual background instead of generated from scratch. This raised autonomous AI answer coverage 88% and cut LLM cost 28% by retrieving facts rather than re-prompting a large model per question.
- Enforced a hard anti-hallucination boundary: a FactGuard layer blocks the model on any field with no retrieved fact, so the agent answers from real data or escalates. It never fabricates on a submission the user cannot take back.
- Built the API layer with FastAPI and Pydantic, validating every model output against typed schemas so malformed LLM responses fail fast instead of reaching a live employer form.
- Built the browser-automation engine that submits on real ATS portals (Greenhouse, Ashby, Lever), with idempotency keys and crash-safe replay guaranteeing no duplicate applications, plus anti-bot and CAPTCHA handling for reliable submission.
- Instrumented the full agent path with LangSmith and OpenTelemetry, tracing every model call, tool invocation and decision, plus a queryable outcome taxonomy and dead-letter queue, so agent behavior is measurable and failures are debuggable.

Stack: Python, FastAPI, Pydantic, LangGraph, LangSmith, Pinecone, RAG, OpenTelemetry, PostgreSQL, RabbitMQ, Docker, GitHub Actions

### Backend Engineer — Atum Labs (Atum Core) (Remote)

Aug 2025 – Nov 2025

Intent-driven, multi-chain stablecoin clearing & settlement network letting payment providers move value across chains through one API.

- Built core Go services for an intent-driven, auction-based settlement platform — payment gateway, solver gateway and on-chain verification — within a ~10-microservice system behind one REST API.
- Built an off-chain quote-auction pipeline on Apache Kafka using per-source topics plus ephemeral per-request correlation topics with TTL-based cleanup, decoupling services into an event-driven flow.
- Implemented a gRPC service (7 RPCs over Protocol Buffers) with a resumable server-streaming feed using monotonic sequence IDs, heartbeat liveness checks and replay-on-reconnect for reliable delivery across disconnects.
- Architected an event-sourced PostgreSQL store with a race-free, two-phase work queue using SELECT FOR UPDATE SKIP LOCKED, giving crash-safe, idempotent settlement across a 20-worker pool.
- Designed a write-only key-custody layer with a pluggable signing backend (encrypted storage plus GCP KMS / HashiCorp Vault / Fireblocks adapters), keeping private keys non-retrievable and signing isolated.
- Containerized the service fleet with Docker, authored Kubernetes manifests and built GitHub Actions CI/CD promoting the exact staging-tested image to production by commit-SHA re-tag.

Stack: Go, Kafka, gRPC, PostgreSQL, Docker, Kubernetes, GCP KMS

### Founder & Lead Backend Engineer — Defipe.io (Remote)

Sep 2023 – May 2025

A derivatives trading protocol with a Go off-chain execution engine — order matching, position lifecycle, margin accounting and liquidation.

- Architected a Go off-chain execution engine for a derivatives trading protocol from scratch, covering order matching, position lifecycle, margin accounting and liquidation logic.
- Built a concurrent order-processing pipeline using goroutines for parallel matching and mutex-protected account state under simultaneous leverage constraints.
- Implemented the liquidation engine and funding-rate mechanism; validated across 10K+ simulated leveraged trades with zero false liquidations in testing.
- Built a low-latency WebSocket server propagating real-time state to 500+ concurrent users; grew to 500+ MAU and a 1,000+ member Discord, and won a $1,000 Soonami Venturethon grant.

Stack: Go, WebSockets, Solidity, EVM

### Blockchain Developer — TechExactly (Kolkata, India)

Feb 2022 – Nov 2022

NFT-marketplace smart contracts and the React frontend that drove them.

- Engineered NFT-marketplace smart contracts with state-machine logic for ownership, settlement and transfer; built the React frontend with wallet connection and on-chain interactions.
- Implemented gasless approvals (ERC-2612 permit), removing a separate approval transaction to cut onboarding friction and user gas costs.
- Wrote test suites covering authorization, ownership transfer and failure paths to 95%+ functional coverage.

Stack: Solidity, React, ERC-2612

## Education

B.Tech, Electrical Engineering — B. P. Poddar Institute of Management and Technology, 2017 – 2021