Wenli Fei

A lightweight web application for validating healthcare reimbursement records. Users can upload a CSV file of records, which are automatically checked against five validation rules — including missing fields, invalid dates, and reimbursement amounts exceeding billed amounts.

I built the backend using PHP 8.5 and Symfony 7, with Doctrine DBAL for MySQL database access and Twig for server-side rendering. Each validation rule is implemented as an independent class, and I wrote PHPUnit unit tests for every rule. A GitHub Actions CI pipeline runs all tests automatically on every push.

A bilingual (Chinese/English) personal recipe website where I showcase my home-cooked dishes. The site features a clean, warm aesthetic with a category-based browsing experience. Visitors can explore recipes by category, difficulty, ingredients, and custom tags — or let AI recommend dishes based on what they're craving.

As the admin, I can manage all recipes directly from the frontend — adding, editing, and deleting dishes with image uploads, all persisted to GitHub as a backend-free data store.

An event discovery application that allows users to search for events by location and keywords, view event details, and save personalized favorites. The system also provides recommendations based on user preferences and location.

I implemented the backend using Java and Spring Boot, integrated the Ticketmaster API for real-time event data, and used MySQL to persist user activity and event information. The application is deployed on AWS EC2, simulating a real-world backend system with API design, data persistence, and cloud deployment.

A location-based social posting application where users can sign up, share posts with images, and connect each post to a real-world location. Other users can then discover nearby posts instantly, making the experience more interactive and location-aware.

I built the backend in Go and used Elasticsearch to power geo-search and nearby post discovery. I also integrated Google Cloud Storage for image handling, implemented JWT authentication with role-based access control, and deployed the system on Google App Engine to practice cloud deployment and scalable backend design.

A real-time chat system built in Java that supports private messaging, group chat, and online user tracking. The project works like a lightweight chat application and helped me better understand how real-time communication systems work at a lower level.

I implemented it using Java Socket programming and multithreading, with custom serializable message objects for communication between clients and the server. On the server side, I used one thread per client and maintained an online user map for message routing, while the client uses a command-line interface with a background listener thread to receive messages without blocking user input.