James Xu
Senior Java Developer at WOYO.com
China
Summary
🤩
RockstarJames Xu is a Senior Java Developer with 14 years of experience building and optimizing back-end systems, currently contributing to production services at WOYO.com from China. He is a pragmatic contributor to high-profile open-source data projects—Presto, Velox, Storm and Apache Beam—where he has improved query performance, added new aggregate functions, fixed complex edge cases, and hardened SQL/IO features. His contributions show deep expertise in distributed query processing, stream processing, and engine internals, including performance-minded fixes like metadata caching and dereference pushdown corrections. Colleagues value his blend of careful code quality (documentation and type fixes) and low-level problem solving across C++, Java, and data-engine architectures. A detail-oriented engineer, he also brings practical ergonomics improvements such as command-line tooling and build-system fixes that make large systems easier to run and maintain.
14 years of coding experience
Github Skills (40)
aggregate10
c-language10
apache-storm10
back-end-development10
clojure-cli10
data-engineering10
big-data10
distributed-systems10
aggregate-functions10
zookeeper10
data-management10
java10
clojure10
javas10
query-parser10
Programming languages (8)
Github contributions (5)
nathanmarz/storm
Apr 2012 - Oct 2013
Distributed and fault-tolerant realtime computation: stream processing, continuous computation, distributed RPC, and more
Role in this project:
Back-end Developer
Back-end DeveloperContributions:60 commits in 1 year 6 months
Contributions summary:James primarily contributed to the back-end logic and core functionality of the storm framework. The user implemented the `storm list` command, which required interacting with cluster information and displaying topology details. Additionally, the user added configuration options, such as overriding the local hostname. Several commits involved refactoring and optimization of internal messaging components for inter-task communication and the virtual port layer, demonstrating an understanding of performance and system architecture.
computationfault-tolerantrealtimerpcstream-processing
apache/beam
May 2017 - Feb 2018
Apache Beam is a unified programming model for Batch and Streaming data processing.
Role in this project:Back-end Developer
Back-end DeveloperContributions:48 commits, 83 PRs, 4 pushes in 9 months
Contributions summary:James primarily contributed to the Apache Beam project by fixing minor typos and inconsistencies in comments and Javadoc documentation, indicating a focus on code quality and readability. Furthermore, the user implemented features such as support for FULL OUTER JOIN in the join library and corrected data type mapping for SQL FLOAT, demonstrating an understanding of data processing and SQL functionalities within the Beam framework. The user also supported TextIO as SQL source/sink and implemented various arithmetic operators, adding support for string operators, which suggests involvement in the core SQL DSL features.
golangpythonstreaming-databeambatch
Find and Hire Top DevelopersWe’ve analyzed the programming source code of over 60 million software developers on GitHub and scored them by 50,000 skills. Sign-up on Prog,AI to search for software developers.