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PROFILE

Jan Janßen

Worked extensively on the pyiron_atomistics repository, delivering robust features and stability improvements for atomistic simulation workflows. Focused on enhancing data parsing, dependency management, and packaging by integrating new libraries such as lammpsparser and vaspparser, modernizing build systems with Hatchling, and expanding support for material property datasets. Leveraged Python, YAML, and Bash to streamline CI/CD pipelines, improve test reliability, and ensure compatibility with evolving scientific computing libraries. Addressed critical bugs in file handling, error management, and test coverage, while also contributing to conda-forge/staged-recipes to enable reproducible packaging and distribution of scientific tools across the broader ecosystem.

Overall Statistics

Feature vs Bugs

53%Features

Repository Contributions

95Total
Bugs
30
Commits
95
Features
34
Lines of code
11,967
Activity Months15

Your Network

909 people

Shared Repositories

906

Work History

April 2026

4 Commits • 2 Features

Apr 1, 2026

Concise monthly summary for 2026-04 focusing on the two repositories: conda-forge/staged-recipes and pyiron/pyiron_atomistics. Highlights include delivering a new Solid DMFT configuration with solver tuning and upgrading critical external libraries to maintain compatibility and improve validation/testing coverage. The work enhances testing reliability, reduces risk of regressions, and supports smoother future upgrades across the DMFT workflow and atomistics tooling.

March 2026

2 Commits • 1 Features

Mar 1, 2026

March 2026: Implemented critical build-system and core-library compatibility updates for pyiron_atomistics. Upgraded hatchling to 1.29.0 and pyiron_base to 0.15.13 across multiple configuration files, aligning with latest tooling and fixes. These changes reduce build failures, simplify CI, and lay groundwork for future library updates. Non-breaking updates focused on dependency management and configuration, preserving existing functionality.

February 2026

2 Commits • 2 Features

Feb 1, 2026

February 2026: Delivered two major library migrations in pyiron/pyiron_atomistics to improve parsing robustness and maintainability: LAMMPS parsing migrated to lammpsparser and VASP handling moved to vaspparser. These changes reduce dependency complexity, improve parsing accuracy, and streamline future feature work. No critical bug fixes reported this month; effort focused on strengthening core data-parsing capabilities and cross-compatibility for molecular simulations.

January 2026

1 Commits

Jan 1, 2026

January 2026 (2026-01) focused on stability and maintainability in the pyiron_atomistics repository. No new features released this month; the primary deliverable was a targeted bug fix for SPHInX error handling and logging within the SphinxBase class. This work improves diagnostic clarity, troubleshooting efficiency, and overall reliability of SPHInX integration.

December 2025

2 Commits • 2 Features

Dec 1, 2025

December 2025 monthly summary for pyiron/pyiron_atomistics. Focused on delivering feature work around elastic properties workflow and improving build reliability through packaging updates. No major bugs fixed this month; emphasis on tests and documentation.

November 2025

3 Commits • 2 Features

Nov 1, 2025

November 2025 monthly summary for pyiron_atomistics focusing on robustness, configurability, and consistent atom typing in LAMMPS workflows. Delivered targeted fixes and enhancements to improve simulation reliability, reproducibility, and business value in HPC environments.

October 2025

1 Commits • 1 Features

Oct 1, 2025

Monthly summary for 2025-10 focusing on the packaging work for NOMAD parser plugins within the conda-forge/staged-recipes repository. No major bug fixes reported this month; primary emphasis was delivering install-ready packaging to broaden accessibility and reproducibility of NOMAD parser plugins.

September 2025

18 Commits • 2 Features

Sep 1, 2025

September 2025 monthly summary for pyiron_atomistics (pyiron/pyiron_atomistics) Key features delivered: - Mendeleev property data enhancements: Updated MENDELEEV_PROPERTY_LIST with new properties and corrections; fixed VASP test dictionary key representation. Commits: f92e18de00c34591b8c68515c0f316f030f07b42. Major bugs fixed: - Robust dictionary initialization in Lammps and Vasp functions: Default dictionary arguments set to None and initialized to empty dicts to prevent uninitialized-dict errors. Commit: c844b556534fdb6524510025e9d75fe04f7bda7a. - Test suite stability enhancements: Refactored assertions to np.all, removed unused periodic table property, and fixed VASP string type comparisons. Commits: 25df2e9fd0951e1293de20d9baa6104e1c18a097; 79e9a93c133bc306c14d1b5fad784dc84d27fb7a. Dependency management and environment upgrades: - Consolidated updates across numpy, matplotlib, pandas, pyiron_base, and mendeleev; CI configurations updated for broader compatibility. Commits include: ee5ab5fdc9c568a513e0359f38b016ce72b3b91b, 752e35b59f63f018ef7b93a11af9989cf5483219, 83d1ff7f71d6b90230cb6718c50f20f88a23fcec, bb10872fa51849d9b581f751d3f1ca89d0642a8d, 4deebfe91dc9139ee3a1b0f015c438b7bcf47e47, 9c7bd46c7cb922693898adb18e93a7ee3d92a4e1, d711b0da597bec32854769e8c3b365ef1d3908ee, c18df999cb20c7a416bf3ec08b1e7bb460ae28c0, 68589d77bb023d4cc4f7a4d7471bd0204fa08b34, 188e0c9f3bc6239b22e495cb43096ed85ae27d61, 4bf060e96b8e11878ccb94d5b96bf2524f620ebe, 6f93b25d86d97879d060abe8635209030ec56fa5, e63b2f08a3f91bf8e5c0c02f93e2fd633f39612a, 03a2cec36541ed7a629e99a92a000620f95d44d0. Overall impact and accomplishments: - Increased robustness and reliability of atomistic workflows, reduced flaky tests, and better readiness for numpy 2.0 and Python 3.11; smoother CI and onboarding for contributors. Technologies/skills demonstrated: - Python, numpy, pandas, matplotlib; Lammps/VASP integration; Mendeleev data; test-driven development; advanced dependency management. Business value: - Faster, more reliable simulation setups, reduced maintenance costs, and improved confidence in results.

August 2025

4 Commits • 1 Features

Aug 1, 2025

August 2025 – pyiron_atomistics (Repository: pyiron/pyiron_atomistics). Key features delivered include modernizing the Python packaging and build process, updating configuration and CI/CD workflows to align with Hatchling, and stabilizing environment and test tooling. Major bugs fixed include a dependency tooling parsing issue due to a missing newline in environment.yml and a misconfigured unit test command impacting code coverage reporting. Overall impact: streamlined packaging and release processes, improved build reproducibility, and more reliable test metrics, enabling faster iterations and cleaner distribution artifacts. Technologies/skills demonstrated: Python packaging modernization (Versioneer to Hatchling), build/configuration/CI/CD workflow updates, dependency tooling and environment handling, test coverage tooling, and configuration management.

July 2025

3 Commits • 2 Features

Jul 1, 2025

Concise monthly summary for 2025-07: Delivered foundational packaging and ecosystem enablement for Microstructpy within conda-forge/staged-recipes, establishing reproducible build/test environments and enabling downstream packaging and distribution for microstructure tooling.

June 2025

2 Commits • 1 Features

Jun 1, 2025

June 2025 monthly summary focusing on key accomplishments across two repositories: pyiron/pyiron_atomistics and conda-forge/staged-recipes. Central outcomes: (1) pyiron_atomistics dependency and compatibility fix for pyiron_base 0.13.0 with environment config updates and import refactor; (2) ontolutils packaging introduced to staged-recipes with comprehensive metadata; (3) these changes improve stability, upgrade readiness, and enable downstream automation.

March 2025

1 Commits • 1 Features

Mar 1, 2025

March 2025: Delivered a new Developer Tool – External Executable Runner in the pyiron/executorlib repository, enabling internal subprocess-based execution of external executables with inter-process communication (send input, read output) and a graceful shutdown workflow. Implemented fixes to the tool’s menu to improve stability and usability. This work establishes a reliable primitive for testing and automating interactions with external scripts, accelerating developer workflows and integration testing.

February 2025

41 Commits • 16 Features

Feb 1, 2025

February 2025 – pyiron_atomistics: Delivered a focused set of feature enhancements and stability fixes that improve parsing, data extraction, and documentation, enabling more reliable end-to-end simulations and faster workflows. Key features delivered include a CI environment update to stabilize builds, integration of LAMMPS and VASP parsers for broader data support, POSCAR content access via get_poscar_content, and expanded data conversion utilities, plus a foundational electronic structure module with targeted bug fixes.

January 2025

8 Commits

Jan 1, 2025

January 2025: Focused on stabilizing the pyiron_atomistics test suite and aligning dependencies to support reliable builds and downstream product quality. Delivered a robust set of test improvements for Sphinx parsing and SCF outputs, and updated dependency bounds to remain compatible with newer atomistics, SciPy, and structuretoolkit versions. These changes reduce flaky tests, improve accuracy, and enable faster feature delivery with greater confidence.

November 2024

3 Commits • 1 Features

Nov 1, 2024

For 2024-11, focused on expanding material property data coverage and maintaining compatibility with evolving dependencies in pyiron_atomistics. The work enhances data completeness for Mendeleev properties and ensures reliable retrieval by aligning with newer mendeleev releases, supporting downstream analyses and simulations.

Activity

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Quality Metrics

Correctness89.4%
Maintainability90.0%
Architecture85.4%
Performance80.6%
AI Usage20.2%

Skills & Technologies

Programming Languages

BashMarkdownPythonShellTOMLYAML

Technical Skills

Bug FixingBuild ManagementBuild SystemsCI/CDCI/CD ConfigurationClass InheritanceCode GenerationCode OrganizationCode RefactoringConda PackagingConfigurationDFTData ConversionData FormattingData Handling

Repositories Contributed To

3 repos

Overview of all repositories you've contributed to across your timeline

pyiron/pyiron_atomistics

Nov 2024 Apr 2026
12 Months active

Languages Used

PythonYAMLBashMarkdownShellTOML

Technical Skills

Data HandlingData ManagementDependency ManagementDebuggingPythonSoftware Development

conda-forge/staged-recipes

Jun 2025 Apr 2026
4 Months active

Languages Used

PythonYAMLTOML

Technical Skills

Build SystemsPackage ManagementPython PackagingDependency ManagementScientific ComputingConda Packaging

pyiron/executorlib

Mar 2025 Mar 2025
1 Month active

Languages Used

Python

Technical Skills

IO HandlingPythonmultiprocessingsubprocess