MuhammadSabbir Hossain

Built a niche social platform addressing digital isolation among elderly users. Uses NID-based identity verification to ensure authenticity, face recognition to reconnect people from their past, and ML-driven recommendations to surface relevant content. Supports real-time chat and multi-language accessibility — designed with empathy, not just engineering.

A specialized transit navigation app designed for Dhaka's complex bus network. The application features a custom routing algorithm that calculates the most efficient direct and multi-transfer (up to 2 transfers) paths between stoppages. Built with an offline-first architecture, it synchronizes bus and distance data from Firebase to a local SQLite database, ensuring instant search results and fare estimations without requiring constant internet connectivity.

A robust .NET 10 RESTful API designed to power a community-driven work-sharing marketplace. The system features a sophisticated escrow engine that secures project budgets throughout the job lifecycle—from bidding to completion. It handles complex transactional logic, including concurrent multi-worker slot allocation, automated payouts, and a 50% worker protection policy for project cancellations. Built for high data integrity using EF Core and PostgreSQL to maintain a reliable, auditable point-based economy.

The production version of Karigor, a full-stack marketplace connecting workers (Karigors) with community projects. Built on a serverless architecture using Next.js and Supabase, it provides a seamless user experience for job posting, bidding, and real-time status tracking. The platform integrates a real-time point-sharing economy with a secure wallet system, allowing users to earn and spend points within the community ecosystem.

End-to-end fleet management system integrating hardware and software. A Raspberry Pi runs YOLOv5 in real time to count passengers through a camera, eliminating the need for manual ticketing. GPS tracking, automated operations, and live analytics are streamed to a Django backend for centralized monitoring and management. The project combines custom IoT hardware, computer vision, and a full-stack web architecture.

Built a mobile land measurement tool that loads cadastral maps (image or PDF) and overlays a gesture-controlled canvas with viewport-to-scene coordinate transformation supporting pinch zoom, damped rotation, and point dragging with a magnifier loupe. Polygon area is computed in pixel space and converted via a pixel-to-feet calibration ratio — set by drawing a reference line over a known physical distance on the map. The Batoyara engine uses half-plane intersection algorithms to mathematically slice polygons to a target area percentage. Both the mobile app and web portal share a single Supabase auth layer — the same user session, profile, and token balance work across both platforms. Transactional emails (OTP, verification) are routed through Resend. Per-action token deduction is enforced server-side, and a subscription expiry date gates premium feature access.

Production backend powering the UIU Competitive Programming Community's online judge. Integrates Judge0 for sandboxed multi-language code execution, Redis for async submission queuing between services, and Docker for containerized deployment. Built to handle concurrent contest submissions reliably — used by real students at UIU.

Designed and implemented a microservices architecture separating library operations and university finance into independent, communicating services. Uses gRPC for low-latency inter-service calls and REST for external-facing APIs — demonstrating a real understanding of when to use each protocol. JWT-secured, with EF Core handling data access in .NET.

Full-stack live support chat system built for scenarios where multiple agents handle incoming visitor conversations. Redis-backed queue automatically assigns visitors to available agents, preventing double-handling. WebSocket connections via Django Channels keep messages instant. Deployed with Docker for consistent environments across dev and production.

Peer-to-peer crowdfunding platform built for university students to raise funds and apply for micro-loans. Lenders can bid competitively on loan requests, creating a transparent auction-based interest system. Includes payment integration, investment portfolio tracking per user, and a review system to build trust across the community.

Service marketplace connecting caregivers with families in need of support. Caregivers can be scheduled, approved, and tracked through an admin dashboard. Includes NLP-powered search with autocomplete for fast service discovery, an integrated chatbot for user assistance, and role-based access control separating admin, caregiver, and client views.