SergeĀ Rielau
Principal Software Engineer at Databricks
Mountain View, California, United States
Summary
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RockstarSerge Rielau is a Principal Software Engineer based in Mountain View who leads SQL feature development at Databricks, bringing decades of deep database experience that began at IBM DB2 and continued through Salesforce. He combines SQL compiler expertise, competitive migration know-how (Oracle/SQL Server to DB2), and practical engineering leadership to shape robust, production-grade SQL surfaces for modern lakehouse architectures. An active contributor to major open-source projects like Delta Lake and Apache Spark, he focuses on error handling, SQL semantics, and test-driven improvements that make complex systems more reliable. Known for translating messy, heterogeneous data into well-shaped "bricks," he pairs pragmatic implementation with thorough documentation. Colleagues rely on him for tough SQL design choices and for making hard-to-follow behaviors predictable and auditable.
4 years of coding experience
English, German, French
Stackoverflow
31reputation
549reached
1answer
0questions
Github Skills (17)
unit-testing10
spark10
delta-lake10
testing10
big-data10
test-framework10
java10
scala10
javas10
sql10
error-handling10
sql-parser9
acid8
analytics8
database6
Programming languages (1)
Github contributions (5)
apache/spark
Apr 2022 - Jan 2023
Apache Spark - A unified analytics engine for large-scale data processing
Role in this project:
Back-end Developer & QA Engineer / Test Automation Engineer
Back-end Developer & QA Engineer / Test Automation EngineerContributions:616 reviews, 3 commits, 49 PRs in 9 months
Contributions summary:Serge primarily contributed to the Apache Spark project by implementing and testing error handling and related features within the SQL module. Their work involved adding new error classes, updating existing ones with SQLSTATEs, and refining the error messages. The user also created and updated unit tests to verify the new error conditions and ensure proper behavior. Additionally, they worked on supporting the identifier clause, including support for parameters and functions.
analyticspythondata-processingsqlapache
delta-io/delta
May 2022 - Nov 2022
An open-source storage framework that enables building a Lakehouse architecture with compute engines including Spark, PrestoDB, Flink, Trino, and Hive and APIs
Role in this project:Back-end Developer
Back-end DeveloperContributions:3 reviews, 5 commits, 1 PR in 6 months
Contributions summary:Serge primarily focused on improving error handling and class definitions within the Delta Lake framework. Their work involved adding parameters to error classes, replacing string markers, and refactoring error-related code. They also modified tests to accommodate changes to error messages and class names. The changes suggest a deep understanding of the internal error handling mechanisms and how they are surfaced to users.
analyticsprestodbflinkbig-dataspark
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