Stefan Zeiger
Senior Software Engineer at Databricks
Frankfurt, Hesse, Germany
Summary
🤩
RockstarStefan Zeiger is a Senior Software Engineer with 17 years of experience specializing in Scala, Java and large-scale backend and database systems, currently driving engineering work at Databricks from Frankfurt. He has a long history at Lightbend/Typesafe and Commerzbank, combining enterprise-grade J2EE experience with modern Scala tooling and compiler-level improvements. An active open-source contributor, Stefan has made notable contributions to Slick, the Scala compiler and sbt—improving database aggregates, build automation on Windows, and query compiler back-ends. He brings deep expertise in backend engineering, build systems and performance optimizations, and often focuses on subtle cross-platform and type-consistency issues that improve developer experience and reliability.
17 years of coding experience
19 years of employment as a software developer
Stackoverflow
1,406reputation
43kreached
23answers
0questions
scala
top-5%
Github Skills (23)
windows-installer10
compiler-development10
packaging10
sbt10
msp10
database-testing10
java10
scala10
javas10
automation10
sql10
database-design10
build-tools10
automations10
jdbc9
Programming languages (12)
Github contributions (5)
slick/slick
Feb 2009 - Jun 2022
Slick (Scala Language Integrated Connection Kit) is a modern database query and access library for Scala
Role in this project:
Back-end Developer & Database Engineer
Back-end Developer & Database EngineerContributions:1563 commits, 321 PRs, 272 pushes in 13 years 6 months
Contributions summary:Stefan primarily worked on database-related tasks, including splitting tests into relational and JDBC specific parts, fixing and improving the implementation of aggregates to ensure proper counting and type consistency, and adding support for the new query compiler back-end. They also introduced code generator improvements, such as allowing override of identity types and including the correct table schema in the tests. The contributions also involved improvements to string operations and various tests for the functionalities.
queryintegratedscala-slicksqldatabase-query
scala/scala
Mar 2014 - Apr 2020
Scala 2 compiler and standard library. Scala 2 bugs at https://github.com/scala/bug; Scala 3 at https://github.com/scala/scala3
Role in this project:Back-end Developer & Automation Engineer
Back-end Developer & Automation EngineerContributions:1 release, 6 reviews, 495 commits in 6 years 1 month
Contributions summary:Stefan primarily contributed to the Scala compiler and library. They focused on improving the handling of spaces in file paths for the Scala build on Windows, addressing issues related to argument files and Ant tasks, and added options for Java memory sizes in partest. Moreover, they implemented features for better performance, including enhancements to BitSet implementations. They also worked on improving the build process, creating the shaded JLine in the sbt build, and making existing methods more efficient.
functional-programmingobject-oriented-programmingscala-libraryscala-programming-languagestandard-library
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