Skip to content
SAJEEL HASAN

Karachi, PakistanOpen to full-stack & backend roles

I build the
systems behind
the product

Software Engineering student and full-stack developer. I build multi-tenant web apps, the APIs and data models under them, and AI agents that do real work.

whoamifull-stack dev · se student
ls ./projectsmail-ai/georate/
echo $FOCUSbackend architecture, system design

I write the part users never see — APIs, data models and infrastructure that stay fast when the traffic isn’t polite.

SHIPPING SINCE 2024FLUTTER → FULL-STACK
(01) About

Started in Flutter. Now I build the stack and the agents on top.

I'm a Software Engineering student and full-stack developer. I build web apps end to end — the interface, the APIs under it, and increasingly the AI layer on top. Most of my work is server-side: schemas, auth, caching, the parts that decide whether a product holds up under real traffic.

Right now I'm going deep on agentic AI and RAG. Building MAIL-AI showed me the gap between a chatbot wrapper and a real agent — one that picks its own tool calls, grounded in pgvector embeddings so it retrieves by meaning, not keyword. The interesting engineering is around the model, not in it.

6Projects Shipped
3Roles Held
5Tech Stacks
2027Graduating
(02) Services

What I actually do

001

Full-stack web apps

Next.js and React front ends in TypeScript, wired to services I build myself. At Marktecs that meant a multi-tenant CRM of 60+ screens and 200+ components — App Router structure, org-scoped routing, and a component system the rest of the team builds on.

002

APIs & backend services

REST APIs on Node and Express over PostgreSQL — schema design, auth flows, and Backend-for-Frontend layers that keep API keys server-side. Plus the unglamorous parts: caching, revalidation, and cutting redundant round-trips.

003

AI agents & RAG

Agentic systems on the OpenAI Agents SDK, where the model decides which tools to call rather than following a script. Semantic search over your own data with pgvector embeddings, and human-in-the-loop approval wherever an agent acts on your behalf.

004

Mobile apps

Cross-platform Android and iOS apps in Flutter, where I started out. Multi-screen navigation, Provider state management, REST integration through Dio, and Firebase for auth and storage.

(03) Selected work

Featured projects

BROWSE ALL (06)
MAIL-AI screenshot
012026

MAIL-AI

Agentic AI email assistant. A two-agent Writer and Reviewer pipeline on the OpenAI Agents SDK that decides its own tool calls, grounded in your past emails through semantic search.

Next.jsTypeScriptOpenAI Agents SDKGeminiSupabasePostgreSQLpgvector
GeoRate screenshot
022026

GeoRate

Full-stack PERN application for persisting and exploring location-based reviews, built around a real-time interactive map.

ReactNode.jsExpress.jsPostgreSQLLeafletVercelRailwaySupabase
Book Finder screenshot
032025

Book Finder

Flutter app to search, view and save favourite books. Firebase Authentication, Cloud Firestore, Dio for API calls, and Provider for state management.

FlutterDartFirebaseProviderDio
Daily Stories screenshot
042025

Daily Stories

Flutter blogging app with secure login and signup, full CRUD across multiple REST APIs, and Secure Storage. State handled with Provider for a responsive UI.

FlutterDartSecure StorageProvider
(04) Technologies

Tech stack

Frontend / Web
Next.jsReactTypeScriptJavaScriptTailwind CSSFramer MotionNext.jsReactTypeScriptJavaScriptTailwind CSSFramer MotionNext.jsReactTypeScriptJavaScriptTailwind CSSFramer MotionNext.jsReactTypeScriptJavaScriptTailwind CSSFramer Motion
Backend & Data
Node.jsExpress.jsPostgreSQLREST APIsSupabasePythonNode.jsExpress.jsPostgreSQLREST APIsSupabasePythonNode.jsExpress.jsPostgreSQLREST APIsSupabasePythonNode.jsExpress.jsPostgreSQLREST APIsSupabasePython
AI & Agents
OpenAI Agents SDKGeminiRAGpgvectorChatbotsOpenAI Agents SDKGeminiRAGpgvectorChatbotsOpenAI Agents SDKGeminiRAGpgvectorChatbotsOpenAI Agents SDKGeminiRAGpgvectorChatbots
Mobile
FlutterDartFirebaseProviderSecure StorageFlutterDartFirebaseProviderSecure StorageFlutterDartFirebaseProviderSecure StorageFlutterDartFirebaseProviderSecure Storage
Tools & Deploy
Git & GitHubVercelRailwayPostmanVS CodeFigmaGit & GitHubVercelRailwayPostmanVS CodeFigmaGit & GitHubVercelRailwayPostmanVS CodeFigmaGit & GitHubVercelRailwayPostmanVS CodeFigma
(05) Experience

Where I've worked

01JANUARY 2026 – JULY 2026

Full Stack Developer

Marktecs

Architected and led frontend development of a multi-tenant e-commerce CRM — 60+ screens and 200+ components in Next.js 15, React 19 and TypeScript — and designed the Backend-for-Frontend layer underneath it.

02JULY 2025 – SEPTEMBER 2025

Flutter Developer Intern

Marfah Technologies

Built responsive mobile interfaces in Flutter and integrated REST APIs for dynamic data handling, working remotely with the team to ship features on schedule.

03MAY 2024 – MAY 2025

Tech Analyst Intern

Aga Khan University’s CIME

Developed a Python-based chatbot guiding visitors and students around the CIME facility, later integrated into a robotic prototype, alongside supporting the simulation systems used in medical training.

(06) Education

Where I studied

012023 – 2027 (EXPECTED)

B.Sc. in Software Engineering

University of Karachi (UBIT)

Focused on full-stack development, databases, and software architecture.

022021 – 2023

Intermediate

Fazaia Degree College Faisal

Completed intermediate studies with a focus on science subjects.

032019 – 2021

Matriculation

V.M Public School

Completed matriculation with foundational education in sciences and mathematics.

(07) Contact

Have a role or a project in mind?

Send me a message — about a role, a project, or something you want built. I read everything and reply within a day.

Let’s work together—Available for work—Let’s work together—Available for work—