Rifat
Bin Siraj

Senior full stack engineer and founder of DrutoAI.

I build AI products

I build production web apps, cloud-native serverless systems and AI products, from the React front end to the NestJS or Spring Boot back end and the AWS underneath. Most of what I build, I also run.

5+
years in production
40+
projects completed
7
products of my own, live
9
open-source npm packages

Work

Products I designed, built and keep running; systems I built for employers and clients; and small open-source tools that came out of that work.

My products

Built and operated under DrutoAI. Each one is live and you can sign up.

DrutoAI

drutoai.com

Pay-per-chat AI platform for Bangladesh with pluggable Claude, OpenAI and OpenRouter models, real-time streaming, Bangla support, usage metering and credit billing. Chat packages are bought through bKash, and it ships as native iOS and Android apps. NestJS, MongoDB, Swagger, React, Vite, TypeScript, Tailwind, Capacitor.

ShopDesk

bot.drutoai.com

Multi-tenant sales assistant for online stores. It answers customers on Messenger, WhatsApp, Instagram and web chat in Bangla or English and takes orders in the conversation. Exactly-once messaging through job-id dedupe, per-conversation locks and compare-and-set claims; 61k lines under 184 test specs. NestJS 11, Fastify, MongoDB, Redis, BullMQ, React, Vite, Docker Compose, multi-provider tool calling with RAG.

AI Call Center

callcenter.drutoai.com

Voice AI agents that take calls for a business. NestJS, Fastify, MongoDB, React, Vite, Redux Toolkit, Tailwind, Vapi voice AI, ShurjoPay.

EduAI

learn.drutoai.com

AI-powered learning platform with a Claude tutor. React, TypeScript, Vite, Tailwind, NestJS, Fastify, MongoDB.

DrutoPay

pay.drutoai.com

Free payment verification for Bangladeshi shops. Payments to a personal bKash, Nagad or Rocket number are confirmed automatically from the payment SMS on an Android phone, with a webhook to the shop's site, plus the official bKash tokenized checkout and Nagad merchant APIs. Android SMS capture, NestJS, REST API.

Baki-Khata

bakikhata.drutoai.com · preview

Credit ledger for small shops, in Bangla and English. When a customer pays by bKash, Nagad or Rocket, the payment SMS on the shop's phone settles their oldest dues automatically (FIFO), with a review queue for unknown numbers, escalating SMS reminders, shareable statements and ageing reports. Append-only ledger, duplicate-safe on transaction IDs, 77 tests. NestJS 11, Fastify, MongoDB, React, Vite, RTK Query, Tailwind. Front end is live; sign-up opens when the API launches.

COD Reconcile

cod.drutoai.com · preview

Cash-on-delivery reconciliation for online shops in Bangladesh. Imports orders and courier payout statements (Steadfast, Pathao, RedX or any CSV), matches every parcel to its order, prices it against a dated rate card and flags short payments, wrong fees, returns charged on delivered parcels, parcels never paid and payouts that never reached the bank. A dispute queue, claim files for couriers and an outstanding-COD dashboard follow; the engine is scored on synthetic replays (100% matching precision). 193 tests. NestJS 11, Fastify, MongoDB, React, Vite, RTK Query, Tailwind. Front end is live; sign-up opens when the API launches.

Payment Shield

paymentshield.drutoai.com · preview

Stops online shops in Bangladesh shipping orders that were never paid. Every bKash, Nagad or Rocket payment a customer claims (by store API, staff entry or a one-time customer link) is checked against the money-received SMS on the shop's own phone: verified, wrong amount, TrxID already used or not received. Payment screenshots are read with OCR (English and Bangla); a rule-based risk score with its reasons decides ship, hold or reject, and an opt-in network of hashed TrxIDs catches one payment offered to several shops. Hold queue, signed webhooks, outcome labels with rule accuracy, and a synthetic fraud benchmark. বাংলা / English. NestJS 11, Fastify, MongoDB, React, Vite, RTK Query, Tailwind, tesseract.js. Front end is live; sign-up opens when the API launches.

Kisti

kisti.drutoai.com · preview

Recurring bKash and Nagad billing for schools, coaching centres, internet providers and gyms. Plans bill every subscriber each cycle on Dhaka dates, with prorated months and one-time fees, and never twice. Payments are matched from the organisation's own SMS by a payer code typed in the Reference, then by payer number and amount, with a review queue for the rest. An append-only ledger, cash receipts and a private payer link. SMS reminders with quiet hours, late fees and dunning stages up to suspension, a collection dashboard, ageing and revenue reports, and signed webhooks so an ISP or gym can act on payments itself. বাংলা / English. NestJS 11, Fastify, MongoDB, React, Vite, RTK Query, Tailwind.

Bitoron

bitoron.drutoai.com · preview

Payout verification for businesses that pay many people from bKash, Nagad and Rocket wallets: riders, refunds, sellers and stipends. A maker builds the payout batch, an approver who did not prepare it approves it within their limit, and the sender works through a checklist. Every sent-money SMS on the sending phone is matched to its line by number and exact amount; wrong amounts, double sends, payments to numbers in no batch and payouts missing at the deadline go to an exceptions queue, and a balance trail finds SMS that never arrived. Reconciliation statements, fee reports, signed webhooks and a batch API, plus a synthetic reconciliation benchmark. বাংলা / English. NestJS 11, Fastify, MongoDB, React, Vite, RTK Query, Tailwind.

Joma-Khoroch

jomakhoroch.drutoai.com · preview

Bookkeeping for small Bangladeshi businesses, built from the bKash, Nagad and Rocket SMS they already receive. Each message becomes a transaction, own transfers are paired so they are not counted twice, and rules or optional AI suggestions sort it into a category; the rest wait in a to-sort queue. Every transaction posts to an append-only double-entry ledger, with cash entries, a chart of accounts, a journal, profit and loss and cash-flow reports, CSV export and a read-only accountant role. বাংলা / English. NestJS 11, Fastify, MongoDB, React, Vite, RTK Query, Tailwind.

ShopVerse

shop.drutoai.com

Full-stack online store. NestJS, MongoDB, React, Vite, Tailwind, Redux Toolkit, AWS S3, JWT.

Job App Tracker

jobs.drutoai.com · preview

Tracks every job application from the emails a candidate already gets. One Google sign-in connects Gmail; confirmations, assessments, interview invites, offers and rejections, including LinkedIn's, are classified by the AI provider the user chooses with their own encrypted key, and move each application forward on a Kanban board. Response, interview and offer rates, stale-application flags, a per-email timeline and an admin monitoring panel. NestJS, MongoDB, React, Vite, Redux Toolkit, Tailwind.

Restaurant SaaS

restaurant.drutoai.com · preview

Multi-tenant ordering platform: each restaurant gets its own branded storefront on a subdomain or path, with delivery, pickup and QR-code dine-in. Owners manage menus with option groups, tables and a live kitchen board over Socket.IO; a super admin approves restaurants, and Stripe Connect pays them out. NestJS 11, Fastify, MongoDB, React 18, Redux Toolkit, Tailwind, Framer Motion. Screenshots use a clearly labelled demo restaurant.

Deploy Hub

deployhub.drutoai.com · preview

Self-hosted, Jenkins-style deploy dashboard: runs each project's deploy script on its server over SSH and streams stdout and stderr to the browser over WebSockets. Keeps every deployment's branch, author, duration, exit code and log; SSH keys are encrypted at rest, with super-admin, admin and member roles. NestJS, Fastify, MongoDB, WebSockets, React, RTK Query, Tailwind. Screenshots use demo servers and projects.

Druto Trade

trade.drutoai.com

AI-assisted crypto trading bot for Binance spot that explains every move. Each cycle screens the watchlist on RSI, MACD, moving averages and Bollinger bands, asks Claude, GPT or Gemini only about notable setups, and checks the answer as structured output; the bot, not the AI, sizes every order within a hard budget, stop-loss, take-profit and position limits. Paper, testnet and live modes behind one interface, with live locked behind a server switch and a typed confirmation. Equity curve, candlestick charts, a full AI decision log, AI portfolio targets, a kill switch and WhatsApp alerts. বাংলা / English landing. NestJS 11, Fastify, MongoDB, ccxt, React, RTK Query, Lightweight Charts, Tailwind. App screenshots use a labelled demo session in paper mode.

Built for employers and clients

Production systems from my roles at Sense & Respond Software and Ghuddy, and freelance client work.

H. Properties website home page in Bangla

H. Properties

Bilingual Bangla and English website for a building construction company in Rajshahi, with an admin panel for project updates and finance pages. HTML, CSS, JavaScript, Vercel.

QA Studio

QA Studio

API testing and QA automation with AI-generated tests from Claude, OpenAI and Gemini, mock servers and API-collection management. NestJS and Fastify microservices, MongoDB, BullMQ, React, Material UI, ReactFlow, Monaco, Vercel AI SDK, MCP, AWS.

ATA governance platform

ATA API governance

API governance and documentation platform with a Spectral-based CLI for OpenAPI linting, and React micro-frontends for the doc portal, governance and pricing. Node.js, Express, NestJS, MongoDB, Redis, MCP.

Sniffer

Sniffer

Defect tracking and QA collaboration with CodeMirror editors and drag and drop. NestJS microservices, Anthropic AI, AWS SQS, KMS and SES, React, Redis, Docker Compose.

Associate 360

Associate 360

HR, payroll and finance suite covering companies, timesheets, salaries, payments and finance. Serverless microservices, DynamoDB Streams, Memcached, Pino.

D2C marketing platform

D2C marketing and campaigns

Campaign building, persona management, communications and approval workflows. Serverless AWS Lambda, DynamoDB, KMS, Cognito, SES, SNS, MJML.

Asset management API

Asset management API

AWS serverless with Lambda, DynamoDB, Cognito, KMS, S3 and SNS, plus Jira and GitHub integrations.

Company management

Company management

Serverless Node.js and React on DynamoDB, Lambda, API Gateway, SNS and SES.

All Things API

All Things API

Serverless Node.js and React on DynamoDB, Lambda, API Gateway, SNS and SES.

Ghuddy hotel booking for users

Hotel booking for travellers

Ghuddy's travel and hotel booking platform with Elasticsearch search, Kafka events and SurjoPay payments. Spring Boot, Spring Data JPA, Spring Security, PostgreSQL, Flyway, Firebase, AWS S3, Swagger.

Ghuddy hotel booking admin

Hotel booking admin

Operations console for the booking platform. Spring Boot, PostgreSQL, AWS S3, EC2, CI/CD.

Open-source npm packages

Small tools for keeping Node.js projects and CI pipelines safe and tidy.

  • vuln-guardian

    Finds vulnerable npm dependencies in a project and applies the safe fixes.

  • secrets-guardian

    Catches leaked API keys and credentials in a repo or staged files before they reach history.

  • postinstall-guardian

    Lists install scripts in node_modules, the most common npm supply-chain attack path.

  • license-guardian

    Fails CI on copyleft or unknown dependency licenses that are not on your allow list.

  • actions-guardian

    Finds GitHub Actions pinned to movable tags and pins them to a commit SHA.

  • crashrelay

    Turns back-end crashes, 5xx responses and error logs into Jira or GitHub issues, without duplicates.

  • crashrelay-browser

    A tiny, dependency-free snippet that reports browser errors to crashrelay.

  • files-to-markdown

    Converts PDF, Word, Excel, CSV, HTML, JSON, text and images to clean Markdown.

  • api-collection-converter

    Converts API collections between Postman, Swagger, OpenAPI, Insomnia, HAR, cURL, RAML, GraphQL, WSDL and AWS API Gateway.

More builds with public code

Smaller full-stack apps whose source code you can read on GitHub.

  • Chatbot Platform

    Multi-tenant chatbot builder: create agents with their own prompts and reference files, then chat with streamed answers from Claude or OpenRouter models. NestJS 11, Fastify, MongoDB, React 18, Vite, TypeScript.

  • ShopFlow ordering and payments

    Users, products, orders and payments through Stripe and bKash tokenized checkout, with webhooks. NestJS 11, Fastify, TypeORM, PostgreSQL, Redis, React 19, Tailwind 4.

  • Secure Notes API

    Note-taking REST API with JWT auth, role-based access and brute-force protection, plus a React front end (secure-notes-web). NestJS on Fastify, MongoDB. API docs.

Private and in development

Code that is not public yet, or apps still being built. Happy to walk through any of them.

  • Bangladesh mobile apps In development

    Five Flutter apps for iOS and Android from one shared template: tutor finder, offline medicine reminder with Bangla medicine names, freelancer job board, Dhaka bus routes with crowdsourced sightings, and neighbourhood shop ordering. Flutter, Firebase, phone OTP sign-in, Bangla and English.

  • Healthcare App In development

    Flutter mobile app with a Node.js (Express) back end that proxies requests to Gemini AI, with audit logging. Early stage.

Experience

Five years of full-stack development, cloud-native serverless systems, AI platforms and software architecture.

  1. Aug 2026 – present

    Software Engineer

    Digital Bridge

    • Deliver features across 5+ independently deployed services (React front end, GraphQL API and resolvers, transportation and refund) on an AWS Lambda returns platform of 80+ microservice repositories.
    • Integrated a pricing rules engine into operator return pricing with action-scoped evaluation, and added bounded, role-gated price overrides plus a persisted return-fee decision honoured by the refund service.
    • Root-caused a silent production bug across five e-commerce integrations (Shopify, WooCommerce, PrestaShop, SFCC) and shipped six fixes.
    • Built a Playwright and TypeScript end-to-end suite for the API and UI, and wrote design docs in GitLab and Confluence.
    • Run multi-repository release batches (dry-run merges, conflict resolution, per-service merge requests) and triage incidents in CloudWatch.
  2. 2026 – present

    Founder and Lead Engineer

    DrutoAI

    • Built a full-stack pay-per-chat AI platform with pluggable LLM providers (Claude, OpenAI, OpenRouter).
    • NestJS and MongoDB back end (JWT, Swagger, usage metering, credit billing) with a React, Vite, TypeScript and Tailwind front end, real-time streaming and Bangla support.
    • Integrated bKash payments and shipped native iOS and Android apps via Capacitor.
  3. Nov 2022 – Jul 2026
    3.7 years

    Full-Stack Engineer

    Sense & Respond Software LLC

    • Architected and delivered 8+ production full-stack applications (React.js, NestJS, Express.js, MongoDB/PostgreSQL) serving 50,000+ active users.
    • Designed RESTful and GraphQL APIs that cut average response latency by 40% via query optimization, indexing and Redis caching.
    • Built and maintained AWS serverless infrastructure (Lambda, API Gateway, S3, Cognito, SNS, DynamoDB, KMS), reducing cloud costs by 20%.
    • Established CI/CD pipelines with automated Jest gates and GitHub Actions, reducing production bugs by 60% and enabling daily deployments.
    • Led architecture decisions and mentored 3 junior engineers through code reviews, sprint planning and pair programming.
  4. Jul 2021 – Nov 2022
    1.4 years

    Software Engineer

    Ghuddy Limited

    • Built back-end microservices and REST APIs for a high-traffic travel and hotel-booking platform using Java and Spring Boot on PostgreSQL with Flyway migrations.
    • Implemented Elasticsearch-powered search and filtering for fast hotel, tour and listing discovery across large datasets.
    • Integrated AWS S3, SurjoPay payments, Firebase notifications, Apache Kafka events and Spring Mail transactional emails.
    • Reduced average API response time by 50% via JPA query tuning and PostgreSQL indexing; achieved 95% test coverage with JUnit and Mockito.

Education

Computer science and engineering at RUET, after science at school and college in Rajshahi, and a paper from my thesis.

  1. 2016 – 2021

    B.Sc. in Computer Science and Engineering

    Rajshahi University of Engineering & Technology

    Graduated with first class distinction. Thesis: clustering-based undersampling using K-means for class-imbalanced data.

  2. 2013 – 2015

    Higher Secondary Certificate

    Rajshahi Govt City College

    GPA 5 in Science.

  3. 2012 – 2013

    Secondary School Certificate

    Rajshahi Govt Naohata High School

    GPA 5 in Science.

Publication

Clustering-Based Undersampling Using K-Means for Class-Imbalanced Data

Rifat Bin Siraj and Emrana Kabir Hashi, Rajshahi University of Engineering & Technology

11th IEEE Asia-Pacific Conference on Computer Science and Data Engineering (IEEE CSDE 2026), Cox's Bazar, Bangladesh, 1–3 November 2026. Accepted

Classifiers trained on heavily skewed data tend to favour the majority class and miss the minority one, which is usually the case that matters. The paper presents a data-level fix: k-means clustering decides which majority-class samples to keep when undersampling. Based on my undergraduate thesis.

Impact

Results from the teams and products I have worked on.

  • 50%

    Faster APIs

    Halved average server response time across services through query optimization, caching and endpoint refactoring.

  • 95%

    Test coverage

    Unit and integration suites (Jest, JUnit, Mockito) in CI/CD, with no production regressions for 18+ months in a row.

  • 60%

    Fewer bugs

    Automated test gates and code-review standards cut the defects reaching production.

  • 5 in 12

    Products in a year

    Led a cross-functional team to design, build and ship five full-stack products on time and to spec.

  • 50k+

    Active users

    Served by the 8+ production applications I architected and delivered at Sense & Respond.

  • 80+

    Microservice repos

    On the AWS Lambda returns platform I ship to at Digital Bridge.

Rifat Bin Siraj

About

I'm a full stack software engineer and AI platform builder in Dhaka with more than five years of experience building and scaling production web apps, cloud-native serverless systems and AI-powered platforms. I work across the stack: React front ends, Node.js, NestJS, Express.js and Java Spring Boot back ends, GraphQL, PostgreSQL and MongoDB, and AWS.

I founded DrutoAI, where I build and run AI products end to end. In past roles I made APIs 50% faster, cut production bugs by 60%, reached 95% test coverage and shipped five products in twelve months.

I speak English and Bengali. Outside work I like travelling.

Languages
JavaScript, TypeScript, Java, SQL, Bash
Front end
React.js, Vite, Material UI, Tailwind CSS, Redux Toolkit, Apollo Client, HTML5, CSS3
Back end
Node.js, NestJS, Express.js, Fastify, Spring Boot, REST, GraphQL, microservices, serverless, JWT and Cognito auth, Shopify, WooCommerce, PrestaShop and SFCC APIs
Data
PostgreSQL, MongoDB, MySQL, DynamoDB, Redis, Elasticsearch, Prisma, TypeORM, Flyway, query optimization
Cloud
AWS Lambda, EC2, S3, API Gateway, Cognito, SNS, SES, DynamoDB, KMS, Secrets Manager, CloudWatch, Serverless Framework
Delivery
CI/CD, GitHub Actions, GitLab CI, Docker, Docker Compose, Apache Kafka, BullMQ, Firebase, Git, Linux
AI and LLMs
Anthropic Claude, OpenAI GPT, Google Gemini, OpenRouter, Vercel AI SDK, MCP, real-time streaming, model routing, RAG, evals, usage metering and billing
Testing
Jest, JUnit, Mockito, Mocha, Playwright, TDD
Also
Capacitor mobile apps, bKash and SurjoPay payments, Agile and Scrum

Contact

Hiring, a project, or a question about something here: send a message and I'll reply by email.