Daniel Hahler
Software-Entwickler at Freiberufler
Berlin, Germany
Summary
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Top expert inNeovim and Vim Ecosystem Development
Daniel Hahler is a seasoned software engineer based in Berlin with 22 years of experience building and maintaining production-grade Python systems, particularly in publishing and web backends. He blends hands-on backend development with DevOps fluency—comfortable in terminals, CI/CD scripting and improving developer workflows—and currently contributes at INFARM while freelancing. Daniel is an active open-source contributor with numerous quality-focused fixes and tests across high-profile projects like Django, pytest, Neovim, Starlette and the Python stdlib, often improving robustness, error handling and test coverage. His work shows a strong attention to tooling and developer experience, from terminal apps and Vim/Neovim plugins to package managers and test runners. Not obvious at first glance: he regularly tackles subtle edge cases (segfaults, plugin version conflicts, tricky parser bugs) that boost long-term maintainability across ecosystems.
22 years of coding experience
12 years of employment as a software developer
Westfälische Wilhelms-Universität MünsterBioinformatik, Bioinformatik at Martin-Luther-Universität Halle-WittenbergAbitur, Englisch, Mathe, Informatik, Sozialwissenschaft, Abitur, Englisch, Mathe, Informatik, Sozialwissenschaft at Söderblom Gymnasium Espelkamp
English, German
Stackoverflow
27,518reputation
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79answers
11questions
authentication
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curl
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git
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php
top-1%
python
top-5%
Github Skills (200)
dependency-management10
difference10
sentry10
restructuredtext10
postgresql10
python10
package-management10
testing10
plugin-development10
vimscript10
command-line-interface10
autocomplete10
bash10
foundation-sites10
coverage10
Programming languages (25)
Github contributions (5)
pytest-dev/pytest-django
Jun 2014 - Mar 2020
A Django plugin for pytest.
Role in this project:
Back-end Developer & QA Engineer / Test Automation Engineer
Back-end Developer & QA Engineer / Test Automation EngineerContributions:12 releases, 334 commits, 429 PRs in 5 years 10 months
Contributions summary:Daniel primarily contributed to the `pytest-django` project by fixing bugs, enhancing test coverage, and improving the testing infrastructure. Their commits addressed issues related to database handling within the testing framework, specifically focusing on ensuring database connections were properly managed during tests. They also addressed bugs related to Django's settings module and its interaction with pytest, ensuring correct behavior with different configurations. The user's contributions also included adding new test cases and improving existing ones to validate the functionality and robustness of the pytest-django project.
pythondjangopython3pytest-pluginpytest
pdbpp/pdbpp
Sep 2017 - Jul 2022
pdb++, a drop-in replacement for pdb (the Python debugger)
Role in this project:Back-end Developer & QA Engineer
Back-end Developer & QA EngineerContributions:2 releases, 11 reviews, 557 commits in 4 years 10 months
Contributions summary:Daniel primarily contributed to the `pdbpp/pdbpp` project by fixing bugs within the Python debugger, including resolving issues where the debugger was not properly handling specific states, particularly related to the `curframe` variable. The user also addressed testing issues and edge cases, such as fixing tests for Python 3.7, and handling completion within the debugger. Their commits demonstrate a focus on improving the reliability and functionality of the debugging tool through targeted code changes and improvements to test coverage.
pythondrop-inpdbpython-debuggerdebugger
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