Md Nasimul Hasan
I build things that handle real traffic and real money.
Production Stack
Delivery History
- 10,000+ learners and ~$165K/yr revenue on the Next.js, Node.js, MongoDB platform I build and operate
- ~68 payment req/sec at peak on the DevConf registration and payment flow I built
- Shipped device-bound auth (ECDSA keys, signed requests, replay protection, session revocation), ending cookie sharing across devices
- Shipped HLS streaming with watch-time tracking, so course progress is measured from real playback
- Delivered payment gateways, multi-course enrollment, quizzes, and assignments end-to-end
- Run production on AWS with Docker, Nginx, Cloudflare, and Sentry, owning releases and incident triage
- Shipped React and Next.js apps for Unilever, Evercare, AKASH, Bengal Meat, and Berger, frontend to deployment
- Modernized the MICROZEN microcredit-automation frontend; ran its deploys and cross-server backups
- Built LISTENYZEN backend integrations for Facebook SDK messaging and SMS workflows
- Delivered Unilever Frontline Academy, a nationwide platform for Unilever's frontline workforce
- Promoted in 12 months, expanding from frontend into backend and production infrastructure ownership
- ~2.2M active users in one month on the Next.js 16 server-rendered platform I built
- Lighthouse 100 / 99 / 100 / 100 for performance, accessibility, best practices, and SEO
- Cut 15 MB+ search and ~12 MB campaign payloads to paginated server-side queries
- Cut the 2-4 min release outage to zero with blue-green deploys on Docker, Nginx, and health checks
- Ran the full app and backend on a 2-vCPU origin via Cloudflare caching and clustered Node workers, database off the public internet
- Instrumented Sentry across browser, server, and edge runtimes for error and latency monitoring
Selected Projects
Learn with Sumit — LMS
10,000 learners couldn't afford broken video or a quiz that lost their progress. Own the platform end to end — HLS video streaming, playback-based watch-time tracking, device-bound ECDSA authentication, quiz and assignment flows, payment gateways — running on AWS with Docker, Nginx, Cloudflare, and Sentry. It supports more than $165K in annual revenue.
Offer Finder — bKash
bKash's campaign and merchant discovery product, built on Next.js 16 with server rendering, streaming, and caching. It reached approximately 2.2 million active users in Bangladesh within one month, scores 100/99/100/100 on Lighthouse, and runs on a two-vCPU origin behind Cloudflare with zero-downtime blue-green deploys.
Distributed Video Streaming
What actually happens when a user uploads a video and 500 people try to watch it simultaneously? Built a proof-of-concept to find out — independent microservices for upload, FFmpeg transcoding, BullMQ job queues, HLS packaging, and MinIO storage. Docker Compose as the orchestration layer.
Semantic Search Engine
Keyword search fails when users describe what they want instead of naming it. Built a semantic product search engine using Pinecone vector embeddings and Google Gemini — understands 'something warm for winter' as intent, not just tokens.
SSHM
I was tired of memorizing IP addresses and SSH flags for every server. Built a terminal SSH manager in Go with a fuzzy-searchable TUI (Bubble Tea + Cobra). Save a host once, connect forever.
Zero Downtime Frontend Deploys with Blue-Green on a Single EC2
A real blue green setup on one AWS EC2 instance with Docker and Nginx that removed the downtime caused by rebuilds and container restarts
Unilever Frontline Academy
Enterprise LMS for Unilever Bangladesh's frontline workforce — hundreds of field employees, multiple device types, zero tolerance for downtime. Delivered production-ready React/Next.js frontend against high-fidelity Figma specs.
Published Work
Adapter Port Architecture In Two Real Codebases
How adapter port architecture turned a 30-file email provider swap and a six-week API delay into boring one-line changes, with the concept explained from scratch.
Read article→Why AI Coding Agents Cost So Much (And How to Cut the Bill)
Claude Code and Codex can burn $50–$100 in an afternoon. Here's where the tokens actually go, why the math is the way it is, and the levers that cut bills by 80%.
Read article→Bézier Curves in JavaScript — From the Math to the Canvas
Every smooth curve in Figma, SVG, or CSS easing is a Bézier curve. Here is how they actually work — built from scratch with interactive demos.
Read article→How Diffie–Hellman Became the Backbone of Modern Encryption
How two strangers agree on a secret key over a public network without ever sending it — the math behind every HTTPS connection and Signal message.
Read article→// let's work together