PulseThread

Inspiration

Last year, my mother was battling cancer, and consistent access to blood became the lifeline for her treatment. During this critical time, I experienced the harsh reality of the current donation ecosystem: chaos and exploitation.

I was personally scammed, sending money for travel costs to a "donor" who never showed up. Beyond the financial loss, the emotional toll was devastating. I spent hours calling 50-60 people from public lists, only to hear they were unavailable, ineligible, or had just donated. Meanwhile, reliance on Facebook posts resulted in agonizing delays; posts got lost in the algorithmic noise, and even when someone commented, there was no way to know if they were actually coming.

I realized that while we have technology to track a pizza delivery in real-time, we are still relying on chaotic phone trees to save lives. I wanted to build "Uber for Blood", a platform that replaces uncertainty with logistics, ensuring transparency, credibility, and a Triple Handshake Protocol to certify every donation. PulseThread was born from the need to stop families from feeling helpless and to protect the goodwill of genuine donors.

What it does

PulseThread is a location-based logistics platform that connects blood requesters with verified donors in real-time.

• Real-Time Discovery: Instead of broadcasting to the void, it uses geospatial queries to alert only eligible donors within a specific radius of the hospital.
• Uber-Like Tracking: Requesters can see the donor accept the request and track their location on a map as they travel to the hospital, eliminating the anxiety of "will they show up?"
• The Triple Handshake: A unique security protocol involving three sequential QR scans (Upon Arrival, After Cross-Match, After Donation) to ensure the donor is physically present and the donation actually occurs.
• Trust & Safety: It filters out ineligible donors (e.g., those who donated <3 months ago) and prevents the "ghosting" common on social media.

How we built it

We engineered PulseThread using React Native and Expo for a cross-platform mobile experience.

• Backend: We utilized Supabase (PostgreSQL) as our heavy lifter, leveraging the PostGIS extension to handle complex geospatial queries (calculating radius and distance) efficiently.
• Maps: We integrated the Google Maps API to provide the familiar navigation interface users expect from ride-sharing apps.
• The "Antigravity" Workflow: We adopted an AI-augmented development approach. We used AI coding assistants to scaffold the architecture and generate boilerplate code rapidly. However, we manually refined the complex logic, specifically, the state machine for the QR verification, and corrected AI hallucinations to ensure the code was production-ready and secure.

Challenges we ran into

• Map Complexity: This was our first time working deeply with the Google Maps SDK. Handling distinct markers for donors vs. hospitals, drawing route polylines, and managing permission scopes on both Android and iOS proved difficult.
• The "Trust" Logic: Designing the Triple Handshake was a theoretical challenge. We had to ensure the flow was strict enough to prevent fraud but simple enough not to annoy users during a medical emergency. Translating this physical workflow into a digital state machine required careful planning.
• AI Integration: While using "Antigravity" (AI assistance) sped up development, it often hallucinated API methods or imported deprecated libraries. Debugging AI-generated code required a deep understanding of the underlying documentation.

Accomplishments that we're proud of

• The Triple Handshake: We successfully implemented a 3-stage QR verification system that updates the database in real-time. Seeing the status change from "En Route" to "Arrived" to "Donated" instantly on both screens was a major win.
• Geospatial Querying: We are proud of writing efficient PostGIS queries that instantly filter donors by blood type, location, and eligibility date, turning a complex database problem into a sub-second response.
• Solving a Real Pain Point: We moved beyond a simple CRUD app to build a logic-heavy solution that directly addresses the trauma of medical uncertainty.

What we learned

• Geospatial Engineering: We gained a deep understanding of how location-based services work, from handling coordinates to calculating Earth-distance using SQL.
• Hardware Integration: We learned how to interface with mobile hardware (Camera for QR scanning, GPS for location) within the Expo ecosystem.
• State Management: We learned that real-time apps require robust state management (using TanStack Query) to ensure the UI doesn't fall out of sync with the server reality.

What's next for PulseThread

• Identity Verification: We plan to integrate National ID (NID) verification and Phone Number Auth (OTP) to create a verified "Blue Tick" system for donors, further reducing the risk of scams.
• Live "Rider" Animation: We want to implement the visual polish of seeing the donor's icon move smoothly across the map in real-time (using interpolation), rather than jumping from point to point.
• Push Notification Infrastructure: Building a robust notification system that wakes up the device even when the app is killed, ensuring critical alerts are never missed.

Built With

• expo.io
• google-maps
• react-native
• supabase