Ruben Lopez
Staff Software Engineer at DataPelago
Las Palmas de Gran Canaria, Spain
Summary
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Rockstar🎓
Top SchoolRuben Lopez is a seasoned software engineer with over 15 years of international experience building backend, distributed, and embedded systems, currently based in Las Palmas de Gran Canaria. He specializes in query optimization and high-availability architectures, with deep Java expertise and hands-on experience across MS SQL Server, Oracle and PostgreSQL. Ruben has driven Calcite-based query planning improvements in commercial products (Theseus, Tibco EBX) and is a long-time Apache Calcite contributor and PMC member, bringing open-source rigor to enterprise systems. He’s recently focused on GPU-accelerated and Spark-oriented query optimization, blending research-grade planner work with production practicality. Notably, Ruben has made core Calcite enhancements—such as making BasicSqlType immutable and improving structured-type nullability handling—that reduce subtle SQL edge-case bugs in large-scale engines.
8 years of coding experience
15 years of employment as a software developer
Bachelor’s Degree Computer Engineering, Bachelor’s Degree Computer Engineering at Universidad de Las Palmas de Gran CanariaMaster’s Degree Complex Software Systems, Master’s Degree Complex Software Systems at Universidad Politécnica de Madrid
Spanish, English, French, German
Github Skills (6)
apache-calcite10
javas10
sql10
datatypes10
java10
relational-databases9
Programming languages (3)
Github contributions (5)
apache/calcite
Oct 2018 - Sep 2022
Apache Calcite
Role in this project:
Back-end Developer
Back-end DeveloperContributions:450 reviews, 97 commits, 312 PRs in 3 years 11 months
Contributions summary:Ruben primarily worked on the Apache Calcite codebase, focusing on enhancing and refactoring core functionalities. Their contributions involved making the `BasicSqlType` class immutable and enabling reuse of existing types. The user also addressed bugs and implemented features such as setting nullability for columns of structured types, thereby enhancing the robustness and flexibility of the SQL processing engine. They also improved code and metadata related to handling edge cases with BigDecimal literals.
geospatialapache-calcitesqlapachebig-data
rubenada/calcite
Oct 2018 - Mar 2025
Mirror of Apache Calcite
Contributions:538 pushes, 136 branches in 6 years 6 months
apache-calciteapacheslingaemjava
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