University of California, Berkeley

Software Engineer at Duolingo

San Francisco Bay Area

Duolingo

Software Engineer

Optimized battery consumption on iOS app by creating buffer module for
cpu-intensive autosuggest calls, reducing in-use power consumption by 40%
without detracting from user experience

Created ChatMySelf feature, a custom chat room designed for self-messaging
and data storage, reducing server load from multiple single person chat rooms
by 37%

LINE Corp

Software Engineering Intern

Part of the consumer video team working on Periscope service

Architected broadcast editing replay feature to existing app using Objective-C that allowed Periscope broadcasters to edit their broadcast metadata such as title, start point, and thumbnail

Twitter

Worked on smart device runing on a minimal operating system, freeRTOS, and created scheduling module in C for ESP32 microcontroller operating on freeRTOS, involving extensive use of synchronization primitives such as Semaphores and Mutexes.

Worked on bare-bones programming in C for STM32L0 microcontroller under limited RAM (16KB) to integrate LoRaWAN RF module into existing smart home device. Made networking module using low level tcp/ip library (LWIP). Migrated Keil MDK-ARM to open source GCC build system using makefiles, startup code, linker scripts, etc.

YoSmart

Created Python modules for integrating functionality of Google Drive API to Kloudless standard API

Made infrastructure updates to existing API modules running on Django framework

Zhecheng Xu