Jax Liu
Designer at HTC
Taiwan
Summary
🤩
Rockstar🎓
Top SchoolJax Liu is a seasoned designer and engineer with 12 years of experience based in Taiwan, currently contributing design expertise at HTC while actively writing backend database code in open source. As an Apache DataFusion committer and contributor to DuckDB, he blends systems-level SQL engine improvements with practical compatibility work—implementing unparsing logic for complex SQL expressions and aligning DuckDB catalogs to PostgreSQL 16. His work straddles design and database engineering, giving him a rare perspective on both user-facing product decisions and low-level data platform internals. Colleagues benefit from his knack for turning nuanced technical specifications into clean, interoperable implementations that make analytical systems more expressive and standards-compliant.
12 years of coding experience
Shih Chien University
Stackoverflow
1reputation
0reached
0answers
0questions
Github Skills (18)
postgresql10
databases10
database-administration10
schema-design10
fusion10
sql10
database-design10
db-schema10
database-schema10
query-engine10
rust10
schema10
relational-databases10
sql-database10
database10
Programming languages (8)
Github contributions (5)
apache/datafusion
May 2024 - Mar 2025
Apache DataFusion SQL Query Engine
Role in this project:
Back-end Developer
Back-end DeveloperContributions:349 reviews, 114 PRs, 38 pushes in 10 months
Contributions summary:Jax primarily focused on enhancing the SQL query engine by implementing new functionalities and improving existing ones. Their contributions involved implementing the unparsing of specific SQL expressions like `IS_NULL`, `IsNotFalse`, and handling `OuterReferenceColumn`. They also added the functionality to unparse `ScalarValue::IntervalMonthDayNano` and improved the string representation of various data types. Additionally, they added the implementation of a dialect-specific rule for unparsing an identifier with or without quotes.
querypythonquery-enginedataframerust
duckdb/duckdb
Dec 2023 - Apr 2024
DuckDB is an analytical in-process SQL database management system
Role in this project:Database Engineer / Database Administrator
Database Engineer / Database AdministratorContributions:4 PRs, 6 comments, 2 issues in 4 months
Contributions summary:Jax's primary contributions involve enhancing the database's compatibility with PostgreSQL. They added several PostgreSQL-specific catalog functions and views, including those related to session information, information schema views, and constraint definitions. Their work also encompassed upgrading the schema of `pg_proc` to align with PostgreSQL 16 and mapping DuckDB's internal object identifiers to PostgreSQL's equivalents.
management-systemanalyticsduckdbmysqlembedded-database
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.