• Updated the iOS frontend of a digital phenotyping mobile health research app and assisted to build out its backend to better support the needs of health research teams; • Migrated the codebase to latest SageResearch SDK and integrated with the existing Sage Bridge SDK (based on Apple’s ResearchKit); used Bridge REST API for authentication and managing users’ health data and survey records.• Improved customized keyboard, whose functionality and cosmetics are 90% close to the default iOS keyboard for research purposes; fixed the cosmetic issues with globe key; added a new scatter chart.• Developed keylogger to record keystroke dynamics; used SQLite to save keystroke data locally then transmit to remote server; fixed the data filtering bug of database and improved the accuracy of keystroke time by 20%.• Written unit tests with XCTest for the authentication page and the arrangement of components in the dashboard page.• Managed dependencies through Carthage; used Git for version control to propagate dependencies for future build.Tools and Technologies: Swift, Objective-C, Xcode, SDKs, ResearchKit, REST API, Git, Carthage, SQLite, JSON, MVC, XCTest

• Used Spring framework to develop a Pet Clinic Application followed Agile concept using Github issues for planning.• Implemented data persistence layer with H2 database using Spring JPA and Hibernate for Object-Relational Mapping; used Spring MVC to structure the application and Thymeleaf template engine to design and render the web pages.• Monitored the whole project using Spring Boot Actuator and resolved clients' requests using WebDataBinder.• Managed dependencies through Maven; used JUnit and Mockito for Test-Driven Development and auto-testing.• Simplified the code using project Lombok and set up Continuous Integration builds with CircleCI.Tools and Technologies: Spring Boot, Spring MVC, Hibernate, Maven, JUnit, Mockito, Project Lombok, Circle CI, TDD

Learned and used LLVM Optimizer (based on C++) to analyze and optimize program; implemented Passes to collect static and dynamic instruction in the function; implemented a generic intra-procedural dataflow analysis framework to express algorithms that compute information of a program; based on the framework, added reaching definition analysis and liveness analysis to analyze the facts propagation; implemented flow function that process three kinds of IR instructions; used different traversal routines to iterate nested data structure in STL algorithms.Tools and Technologies: C++, LLVM, Docker, dataflow analysis

Used C to implement the Unix kernel function of process management including creation, scheduling and inter process communication (using shared memory and semaphore); implemented the thread function such as thread creation, saving and restoring context; combined the functions with internal function calls to construct a simple OS.Tools and Technologies: C, Unix, kernel modules, process, thread, semaphore

Designed an indoor location-aware software system based on RFID in C++ (Won outstanding project prize); implemented LANDMARC and VIRE algorithms to process the fingerprints; used reader’s API; developed a GUI (MFC framework) with TeeChart ActiveX in constructing 3D views; auto-generated error estimation diagrams.Tools and Technologies: C++, Visual Studio, MFC, MVC, TeeChart ActiveX, algorithms