Md Sajjadur Rahaman
Full Stack Developer · DevOps Engineer · AI Engineer
$ cat /engineers/md-sajjadur-rahaman.md
Full Stack Developer building end-to-end products across frontend, backend, and cloud infrastructure. Experienced in shipping scalable web platforms, API-driven services, and AI-powered features with production reliability.
Status: building production full-stack products with AI + cloud
$ render --scene cloud-core --links realtime
Cloud Mesh
edge ingress
AI Core
inference bridge
Runtime
service layer
Data Layer
persistence
$ profile
About Me
The engineer behind the systems — what I build, how I think, and where I focus.
Md Sajjadur Rahaman
Also known as Likhon
Full Stack Developer · DevOps Engineer · AI Engineer
I'm a full stack developer who enjoys taking products from an empty repo to production, designing the API, provisioning the infrastructure, and shipping the interface that sits on top. Most of my depth is on the backend and DevOps side: scalable services in Laravel and Express, data modeling in MySQL and MariaDB, and deployment through Docker, Nginx, and CI/CD pipelines.
Lately I've focused on bringing AI into real products, secure API integrations, usage tracking, and features built on OpenAI and Azure AI. What I care about most is clean architecture, production reliability, and code that's still easy to work with a year later.
$ systems
Latest Projects
Recent production systems across backend APIs, real-time services, and cross-platform products.
System
Flowpamine: Project Management SaaS API (Laravel 13 Modular Monolith)
Ground-up rewrite of a project-management SaaS API as a modular monolith, with an LLM agent that turns WhatsApp conversations into tasks under human approval.
$ service/modular-monolith-api
Modular Monolith API
- 8 bounded modules communicating through domain events, not direct calls
- 120 documented endpoints across 55 tables with a generated OpenAPI specification
$ service/llm-agent-layer
LLM Agent Layer
- Converts WhatsApp conversations into tasks, notes, and files under human-in-the-loop approval
- Ports-and-adapters abstraction over six providers with a deterministic offline fallback
$ service/delivery-&-reliability
Delivery & Reliability
- Transactional outbox over Redis Streams consumer groups with a dead-letter stream
- Lease and claim semantics, stale-message reconcilers, and separate retry budgets
System
Flowpamine: AI Project Management & Knowledge App (Desktop)
Offline-first AI project management and knowledge organization desktop app.
$ service/desktop-workspace
Desktop Workspace
- Workmap, Canvas, Kanban, Calendar, and Card Library in one app
- Unified workspace for projects, tasks, notes, and documents
$ service/ai-intelligence-layer
AI Intelligence Layer
- Local LLM-powered summaries, task breakdowns, scheduling, tagging, and related ideas
- Optional cloud AI for heavy tasks like document merge and canvas organization
$ service/rag-&-semantic-search
RAG & Semantic Search
- RAG recommendations and vector search across notes and documents
- Semantic caching with LRU + TTL for faster repeated responses
System
Multi-Tenant Hotel Management SaaS (Backend Lead)
Multi-tenant hospitality platform with a pluggable four-driver payments layer and white-label custom-domain hosting.
$ service/multi-tenant-core-api
Multi-Tenant Core API
- 62 models, 83 migrations, and ~290 versioned endpoints behind 116 service classes
- Four-tier platform, owner, staff, and guest access model with per-property RBAC scoping
$ service/pluggable-payments-layer
Pluggable Payments Layer
- Four gateway drivers behind a single contract and registry
- Idempotent webhook-event recording with per-gateway signature verification
$ service/white-label-domain-hosting
White-Label Domain Hosting
- Domain-verification records with token, status, and timestamps plus a conflict detector
- Edge middleware resolves the incoming Host header to a tenant on every request
$ career
Experience
Roles across full-stack engineering, backend development, and freelance product work.
MTS Innovation Sdn Bhd
Full Stack Engineer
October 2023 – Present
Kuala Lumpur, Malaysia
Huacomm Telecommunications Engineering (M) Sdn Bhd
2 yrs 1 moJunior Software Developer
February 2022 – September 2023
Kuala Lumpur, Malaysia
Software Engineer Intern
September 2021 – January 2022
Kuala Lumpur, Malaysia
Independent Contract Engagement
Freelance Full Stack Engineer (Contract)
Remote
Freelance
Freelance Web Developer (PHP/Laravel, MySQL, JavaScript)
$ capabilities
Core Competencies
Full-stack depth across frontend, backend, cloud, and AI integration for shipping reliable digital products.
- Frontend Engineering
- Next.jsReact + TypeScriptTailwind CSS, Shadcn UIResponsive UI architectureAccessible component designPerformance-focused UX
- Backend & APIs
- LaravelWinterCMSExpress.JSRESTful APIsAuthentication & authorizationCron jobs & Queue processing
- Databases & Data
- MySQL, MariaDB, PostgreSQLMongoDB, SQLiteRedis, MemcachedRelational schema designData modeling and optimizationLarge-scale exports and reporting
- Cloud & DevOps
- Linux (Ubuntu, CentOS, Amazon Linux)Docker, KubernetesNginx, ApacheCI/CD pipelines, AutomationCloud deployment and cost optimization
- AI & Integrations
- OpenAI APIAzure OpenAI / Azure AI ServicesGoogle Gemini APIAnthropic Claude APISecure API integrations
- Platforms
- iOS, iPadOS, macOS, tvOS, watchOS, AndroidWindows and Linux desktop environmentsSwiftUI (shared multi-target architecture)Expo / RN, Flutter, Tauri, Kotlin Compose
$ education
Education
Academic background in information technology and computer science.
School
Universiti Tenaga Nasional
Graduate coursework, Information Technology (no degree)
2022 – 2023
Kajang, Malaysia
School
City University Malaysia
Bachelor of Science (BS), Computer Science
2019 – 2022
Petaling Jaya, Malaysia
School
Malvern International Academy Malaysia
High School Diploma, Computer Technology
2016 – 2019
Kuala Lumpur, Malaysia
$ engineering focus
How I Build
Full-stack systems designed for usability, scalability, security, and long-term maintainability.
01
End-to-end product ownership from UI to infrastructure
02
Clean architecture across frontend and backend layers
03
Scalable APIs and resilient distributed services
04
Production observability, reliability, and performance
05
Security-first development and integration patterns
Contact
Let’s Build Something Reliable
Open to backend engineering, DevOps, and AI systems work where architecture quality, performance, and production reliability matter.