Li Chen

An AI-powered online learning web application that features a user-centric learning portal and a content management system, both hosted on AWS CloudFormation.

As a full-stack developer, my responsibilities included implementing new features using Clojure and ClojureScript, addressing bugs, and optimizing performance.

The project involves a cold storage crypto wallet designed with encrypted hardware. The accompanying web application enables users to initialize or unlock the wallet, view transaction history, execute transactions, and exchange between various cryptocurrencies, with any sensitive operations protected by requiring physical interaction on the device. I am the main developer, and the web application was developed using Clojure and ClojureScript.

The back end handles transaction broadcasting, performs interactions with third-party APIs, handles payments, and carries out validation on local blockchain nodes and user-obfuscated data storage.

Communication between the front end and back end occurs through REST API and WebSockets. The application features integration with payment channels such as Alipay and PayPal.

Additionally, the front end interacts with the hardware wallet through WebUSB technology.

The Chipsea platform empowers clients, who are manufacturers or distributors, with the ability to manage licenses, release mobile applications, create and publish new posts within their mobile apps, organize events or launch promotions, and review user statistics and automated email communications. This comprehensive tool streamlines various tasks, making it an essential resource for Chipsea clients.

I am responsible for the database and the multi-module back end, as well as the CMS front-end development. In this project, I used Clojure on JVM, MySQL, Redis, and MQTT in the back end and Clojurescript in the front end. ELK is integrated into the platform to collect logs and provide valuable business insights. Thrift RPC protocol is integrated among the back-end modules, allowing inter-module interaction.

This web app is designed for use inside WeChat (as a WeChat mini program) or on normal browsers. It enables remote monitoring of sensors through various protocols, data aggregation, and user control over irrigation and ventilation systems. Additionally, users can configure WiFi through WeChat and create plans to automate these operations based on a set of custom-defined rules, offering a seamless and efficient experience.

The robot is built on Rockchip 3288. It supports multiple motors and sensors, utilizing standard connectors; it also has hotplug capabilities.

I developed the daemon using Rust and the robot's UI with Electron and ClojureScript. The daemon interacts with the driver, handles Bluetooth controller events, controls motors and sensors and collects sensor data, manages and executes user applications (usually written in Python), provides WebSocket or UDP interfaces for the robot's front end, and exposes REST and Websocket APIs for the IDE, which typically runs on a PC. Additionally, I created several demo user applications in Python to showcase the robot's capabilities.

The exhibition features numerous technology zones and dozens of interactive digital art kiosks.

I developed the back end and management website for the gallery, along with several front-end applications. Additionally, I was responsible for programming most of the sensors involved in the interactive exhibits.

The project involves a cross-platform mobile app designed for use with a USB-powered Bluetooth thermometer. The app offers temperature calibration, measurement, firmware updates, and access to historical data. Additionally, a web app is available for logged-in users to view relevant statistics and analytics.

The platform enables users to trade a variety of items, including both physical and virtual goods. As part of the development team, I maintained and added new features to a component offering APIs for enterprise clients. This component processes trading requests and supplies real-time market information. I also implemented cache and queue layers to ensure only valid trade requests reach the matching system.

A healthcare monitoring web app that tracks sensor data, including blood pressure, heart rate, SpO2, and more, from our healthcare smartwatch and tablets. The app manages users, detects abnormal health conditions based on sensor data, and sends notifications to authorized guardians. My contributions included building the database and back end that provide REST APIs to mobile apps, customizing the Openfire instant messaging system to suit our use cases, and creating another web app tailored for the hospital to manage the doctors and patients.

A fuzzing tool for identifying bugs in EVM-based smart contracts. My contributions included adding instrumentation to the open-source EVM implementation, which enabled the fuzzing tool to capture essential signals for bug detection. Furthermore, I created flattening, parsing, and binary-to-source mapping tools using Python to enhance the tool's functionality.

In addition, I built a web app that enables users to upload, edit, and analyze smart contracts.