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SM AFTAB HOSSAIN — PORTFOLIO © 2026

RAFAEL

AI ENGINEER DHAKA, BD — 23.81°N 90.41°E
SCROLL TO EXPLORE ↓ AVAILABLE FOR INTERESTING PROBLEMS EST. 3+ YRS
AI VOICE AGENTS RAG PIPELINES LLM ASSISTANTS DOCUMENT AI VECTOR SEARCH PSTN ↔ WEBRTC COST-AWARE AI
01 — About

I teach machines to read, reason, answer — and pick up the phone. At Vivasoft I ship production AI: a voice agent platform that talks over real phone lines, RAG systems over healthcare trial data, document intelligence with OCR, and agents that qualify leads while the sales team sleeps. Built on a data-engineering backbone, designed to survive reality.

The craft

Full journey of an AI product: ingestion → embeddings → retrieval → generation → deployment. Retrieval quality beats model size, every time.

The backbone

Airflow DAGs, BigQuery, Terraform, SQL tuning. Boring infrastructure is why the exciting parts don't fall over.

The receipts

6 AI products in production across voice, healthcare, HR tech, sales ops, and enterprise support. Trusted in client and sales meetings as the engineering voice. B.Sc. Software Engineering, IUT '22.

02 — Selected Work

SIX AI PRODUCTS.
ALL IN PRODUCTION.

scroll → the page moves sideways
01
Voice AI — Platform

Kothon

Vivasoft's AI voice agent platform. I built the agent's memory — a low-latency RAG stack with Docling parsing, Chonkie chunking, Weaviate, and Azure multilingual embeddings — and the telephony connector bridging PSTN calls from PBX with the agent's WebRTC calls via PJSUA/SIP, so the AI talks on real mobile numbers.

→ an AI that answers the phone, in more than one language
PJSUA / SIPWebRTCDoclingChonkieWeaviate
02
Sales Ops — AI Agent

Lead Qualifier

Autonomous agent that evaluates every lead from Vivasoft's social media and website. Webhooks pull leads from Pabbly and WordPress, Gemini rates them against qualification criteria, qualified ones flow into the CRM via API, and the sales team gets pinged on Telegram. Hosted on GCP.

→ no lead sleeps in an inbox anymore
GeminiWebhooksPabblyTelegram APIGCP
03
Healthcare — RAG

Aurora

Chat system for Health Technology Assessment trial data. CSV ingestion via Azure Functions into Azure SQL, vectorized into Azure AI Search with LangChain + Azure OpenAI. Dynamic filters by country, drug, and agency with full conversation memory.

→ complex regulatory data, answerable in one question
FastAPILangChainAzure OpenAIAI Search
04
Document AI — OCR

Document Extraction Platform

Full-stack document intelligence. Gemini-powered OCR extracts key-value pairs, bounding boxes, and confidence scores; humans validate the low-confidence tail. Template management and role-based workflows, containerized on Azure.

→ scanned paper in, structured data out
Gemini APIFastAPIMongoDBDocker
05
Support — RAG

AiPEN

RAG assistant for internal support and customer queries. Led ingestion, embedding, and GPT response generation. Real-time analytics for query monitoring and feedback trends, plus a feedback loop that keeps sharpening accuracy.

→ support that learns from every conversation
WeaviateAzure OpenAIFastAPIDocker
06
HR Tech — Assistant

PiHR Assistant

In-app AI guide for an HR platform — feature help and UI navigation via vector search + GPT-4o mini. Secure isolated backend, and an OpenAI cost-monitoring dashboard so the bill is never a surprise.

→ LLM products die when nobody watches the bill
GPT-4o miniLangChainWeaviateFastAPI
Also built
Report-SchedulerJava Spring · scheduled CSV reports + SMTP, on Linux
MoodIoT home automation · C++, MQTT, Arduino
IUT-ian AppCampus life app · Java, React Native
Log ProcessorGo · crawler-log filtering → CSV reports
Kothon DemosGemini Live API demo sites · Artifact Registry + Cloud Run
03 — Experience

WHERE I'VE SHIPPED

2024 — NOW

Vivasoft · Software Engineer

Core engineer on Kothon, the AI voice agent platform — agent memory (RAG) and PSTN↔WebRTC telephony. Plus RAG assistants, document intelligence, lead-qualifying agents, and the ETL underneath (Airflow, BigQuery, Terraform). Bridge between engineering and clients in project & sales meetings.

AI / DATA
2023

Trust Axiata Digital · Junior Software Engineer

Modernized SQL Server jobs and stored procedures; built data pipelines powering BI and reporting across departments.

DATA ENG
2021

ShunBoi · SWE Intern

Responsive UI design and build — Flutter, Adobe XD, Figma.

FRONTEND
2018 — 22

IUT · B.Sc. Software Engineering

Islamic University of Technology, Gazipur, Bangladesh.

EDU
04 — Arsenal

TOOLS OF THE TRADE

PythonFastAPILangChainRAG Azure OpenAIGeminiGPT-4oWeaviate Azure AI SearchEmbeddingsOCRGo JavaC++SQLMongoDB PostgreSQLRedisMSSQLAirflow BigQueryDockerTerraformAzure GCPCloud FunctionsCloud RunSQLAlchemyGit WebRTCSIP / PJSUADoclingChonkieGemini Live
05 — Talk to my AI

ASK RAFAEL-BOT

rafael-bot v2 · runs in your browser · 0 tokens billed
Have an interesting AI problem?
LET'S BUILD IT
email ↗ github ↗ linkedin ↗
USUALLY REPLIES WITHIN A DAY · DHAKA, BD (GMT+6)