Developed the mobile app, Snackpass, and test frameworks with React Native, Redux, and Jest.

Graduate Teaching Assistant for Computer System.

Helped the professor to prepare materials for the class. Made beta tests for quizzes, assignments and exams to fix bugs and errors, and confirm the difficulty and workload are suitable for students.

Answered student questions, helped debug assignments, and reinforced materials taught in the class.

Full-stack engineer on the Listnr which manage survey-based user feedback from Google products.

Wrote design doc of Question Template which are well-formed questions and can be reused to build new surveys. It supports placeholders allowing users to replace with actual value.

Implemented CRUD operations and preview of Question Template from UI, backend to databases with AngularJS, Google Spreadsheet API and other internal frameworks.

Developed a big data platform based on Hadoop, and mainly focused on encapsulating the functionality of DataFrame, RDD, and mllib to build visual data analysis tools, and tuning and optimizing the performance of Spark.

Extended the features of OLAP functions for sql parser of HyperSQL DB based on SQL:2011, and modified HyperSQL DB to support database link.

Analyzed Apache Spark's source code, especially for the parts of task scheduling, RDD and data source.