John Parejko
Astronomer at University of Washington
Seattle, Washington, United States
Summary
🤩
Rockstar🎓
Top SchoolJohn Parejko is an astronomer and software engineer with 12+ years building high-performance data pipelines and telescope operations software, currently on the Vera C. Rubin Observatory Data Management/Alert Production team at the University of Washington. He brings rare end-to-end expertise from on-telescope operations at SDSS to large-scale, low-latency data processing, writing production C++ and Python (pybind11) to meet 60-second alert windows while keeping rigorous test-driven practices. A dedicated open-source contributor, he has improved FITS handling and integrated Lupton RGB scaling in the widely used Astropy ecosystem and strengthened SDSS access tests in Astroquery. Beyond shipping reliable pipelines, he obsessively optimizes Python for multi-core environments and bridges legacy packages with clean APIs, which reflects both practical engineering and deep domain knowledge from a Ph.D. in physics.
12 years of coding experience
7 years of employment as a software developer
Doctor of Philosophy (Ph.D.), Physics, Doctor of Philosophy (Ph.D.), Physics at Drexel UniversityBachelor's Degree, Physics, Bachelor's Degree, Physics at Carleton College
German, Spanish, Hungarian
Github Skills (11)
fits10
astropy10
pytest10
python10
astrophysics10
astronomy10
testing10
numpy9
image-processing8
sql8
documentation7
Programming languages (13)
Github contributions (5)
astropy/astropy
Apr 2016 - Oct 2022
Astronomy and astrophysics core library
Role in this project:
Back-end Developer
Back-end DeveloperContributions:13 reviews, 62 commits, 13 PRs in 6 years 7 months
Contributions summary:John contributed to the `astropy/astropy` repository by fixing bugs related to the handling of FITS files, particularly the `CompImageHDU` class. They addressed issues in the placement of the `TFIELDS` keyword and other header keywords within compressed image HDUs. Additionally, the user implemented the initial integration of Lupton RGB scaling from the lsst.afw.display library. Further contributions included cleaning up docstrings and refactoring tests.
astrologypythonscienceastrophysicsastrodynamics
astropy/astroquery
Oct 2015 - Oct 2015
Functions and classes to access online data resources. Maintainers: @keflavich and @bsipocz and @ceb8
Role in this project:QA Engineer / Test Automation Engineer
QA Engineer / Test Automation EngineerContributions:6 commits, 1 PR, 19 comments in 2 days
Contributions summary:John primarily contributed to the testing framework of the astroquery library. They added and modified tests within the `astroquery/sdss` module, focusing on testing the query payload, coordinate handling, and URL construction. These changes improve test coverage and ensure the correct functionality of the SDSS data access capabilities within the library. The commits include adding tests to verify the SQL queries and image retrieval, ensuring robust functionality of the astroquery module.
pythondataastropy-affiliatedastropyastronomy
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