CF Bolz-Tereick
Software Engineer
Duisburg, North Rhine-Westphalia, Germany
Summary
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RockstarCF Bolz-Tereick is a seasoned software engineer with 21 years of experience specializing in dynamic language implementations, JITs, and compilers. Based in Duisburg, Germany, they contribute regularly to PyPy and CPython, focusing on core interpreter behavior and rigorous test automation. Their open-source work includes extending object models, refining floating-point/math semantics in the Topaz Ruby implementation, and fixing subtle AST and unittest issues in CPython—demonstrating a blend of language runtime expertise and quality-first engineering. They excel at iteratively evolving core language features, from instance and attribute semantics to numerical edge cases like NaN and infinity. Colleagues appreciate their deep understanding of interpreter internals and pragmatic approach to refactoring low-level systems.
21 years of coding experience
Github Skills (12)
testing10
unit-testing10
floating-point10
float3210
object-oriented-programming10
software-design10
numerical-methods10
python10
unit-test10
ruby10
pickle9
documentation6
Programming languages (22)
Github contributions (5)
aosabook/500lines
Feb 2014 - Oct 2015
Role in this project:
Back-end Developer
Back-end DeveloperContributions:69 commits, 1 PR, 12 comments in 1 year 7 months
Contributions summary:CF contributed to an object model implementation, expanding its functionality across multiple stages. They implemented core object model features, including instance creation, attribute access and modification, method binding, and support for special methods like `__getattr__` and `__setattr__`. Their work progressed iteratively, introducing features and refactoring code to improve the model's capabilities.
linesmodular-designlistsjava
python/cpython
Aug 2022 - Aug 2022
The Python programming language
Role in this project:Back-end Developer & QA Engineer / Test Automation Engineer
Back-end Developer & QA Engineer / Test Automation EngineerContributions:59 reviews, 2 commits, 34 PRs in 7 days
Contributions summary:CF primarily focused on bug fixes and enhancements within the Python programming language core, specifically related to the `ast` module. Their contributions involved correcting issues in the `ast.BinOp` handling, ensuring correct line number information, and improving the unit tests. The user also contributed to documentation and corrected behaviors within `unittest` and `pickle`. These commits indicate a strong focus on testing and quality assurance within the project.
python-programmingprogramming-languagepythonpython-programming-language
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