Stamatis Zampetakis
Senior Staff Software Engineer at The Apache Software Foundation
Paris, Ile-de-France
Summary
🤩
Rockstar🎓
Top SchoolStamatis Zampetakis is a Senior Staff Software Engineer based in Paris with 8 years of experience building and optimizing distributed data systems and query engines. He brings deep expertise in back-end development, test automation, and performance tuning demonstrated by contributions to high-profile Apache projects like Calcite, Avatica and Hive where he fixed critical bugs, reworked runtime struct access, and modernized testing infrastructure. At Cloudera he progressed through senior technical roles and also plays an active governance role in The Apache Software Foundation as a long-standing Calcite PMC member and former chair. His background blends rigorous academic research on scalable RDF and Hadoop-based query optimization with practical production engineering, making him adept at turning complex query semantics into robust, maintainable implementations. An understated strength is his focus on testability and refactoring—improving code health and reducing technical debt across large open-source codebases.
8 years of coding experience
12 years of employment as a software developer
Master of Science (M.Sc.) Computer Science, Master of Science (M.Sc.) Computer Science at University of CreteResearch Doctorate Computer Science, Research Doctorate Computer Science at Paris-Sud University (Paris XI)
English, French, Greek
Github Skills (19)
apache-calcite10
testing10
big-data10
calc10
java10
javas10
junit10
sql10
performance-optimization10
relational-algebra10
test-automation10
debug9
debugging9
database8
sql-database8
Programming languages (9)
Github contributions (5)
apache/calcite-avatica
Jan 2019 - Dec 2022
Apache Calcite Avatica
Role in this project:
Back-end Developer & Test Automation Engineer
Back-end Developer & Test Automation EngineerContributions:38 reviews, 11 commits, 33 PRs in 4 years
Contributions summary:Stamatis focused on improving the Avatica project by addressing bugs, enhancing testing infrastructure, and refactoring code. They implemented parameterized unit tests for struct accessors, improving data type handling. The user also updated the testing framework by replacing legacy assertion utilities with more modern Hamcrest matchers, increasing maintainability. Furthermore, the user contributed to streamlining the project by removing obsolete JavaScript files and updating dependencies.
geospatialapache-calcitesqlapachebig-data
apache/calcite
Aug 2018 - Jan 2023
Apache Calcite
Role in this project:Back-end Developer
Back-end DeveloperContributions:341 reviews, 125 commits, 304 PRs in 4 years 6 months
Contributions summary:Stamatis implemented structured-type access within the Enumerable runtime, eliminating the DOT operator and translating field access expressions into calls to the `SqlFunctions.structAccess` method. They also added a new test schema and unit tests with queries to access fields of struct types. Furthermore, the user contributed to adding a variant of `FilterProjectTransposeRule` that could push down a Filter containing correlated variables, while addressing an issue with Windows. This work involved modifying existing code and creating tests to validate the changes.
geospatialapache-calcitesqlapachebig-data
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