EXCEEDS logo
Exceeds
Derek T. Jones

PROFILE

Derek T. Jones

Daniel Johnson developed robust data analysis and processing tools for astronomical datasets, contributing to repositories such as astronomy-commons/lsdb and lincc-frameworks/nested-pandas. He engineered features for data onboarding, catalog access, and distributed processing, using Python and Pandas to streamline workflows and improve reliability. His work included implementing in-memory pipelines, optimizing Parquet data handling with fsspec, and enhancing error reporting for Dask-based operations. Daniel also delivered reproducible tutorials and technical documentation, supporting onboarding and data exploration. His approach emphasized maintainable code, comprehensive testing, and performance optimization, resulting in scalable, user-friendly solutions for large-scale astronomy data engineering challenges.

Overall Statistics

Feature vs Bugs

86%Features

Repository Contributions

98Total
Bugs
8
Commits
98
Features
50
Lines of code
88,863
Activity Months13

Work History

October 2025

12 Commits • 7 Features

Oct 1, 2025

October 2025 focused on stabilizing dependency management, enabling rapid, reliable updates, and delivering targeted tooling and performance improvements across five key repositories. The work combined stability improvements, new tooling, a critical bug fix, and performance optimizations to support scalable data workflows and developer productivity.

September 2025

1 Commits

Sep 1, 2025

September 2025: Hardened data pipelines in lsst-sitcom/linccf by removing the deprecated radecMjdTai column from the data schema. The change spans data import, post-processing, and validation logic, ensuring the system gracefully handles the column's absence and prevents runtime errors. This reduces schema coupling and enables smoother future schema evolution, delivering more robust data processing for downstream analytics.

August 2025

7 Commits • 5 Features

Aug 1, 2025

August 2025: Delivered notable backend tooling and data handling improvements across multiple repositories. Implemented a new data source alias for Dash notebooks, added a feature-rich S3 data migration tool with age-based gating, dry-run capability, and concurrency controls, enhanced Dask error reporting and documentation, and expanded nested data access capabilities in the nested-pandas project. These efforts increased data flexibility, governance, observability, and developer productivity, enabling faster data operations and more reliable dashboards across teams.

July 2025

13 Commits • 6 Features

Jul 1, 2025

July 2025 performance snapshot: Delivered high-impact features and stability fixes across four repositories, driving data reliability, scalability, and developer experience. Key outcomes include tutorial path reliability and Rubin data path updates in LSDB, a new append_columns capability and index-preserving fixes in NestedFrame, cross-referenced documentation via intersphinx, a Dask-based guidance notebook for distributed astronomy workflows, and broader notebook configuration/data-handling robustness in Linccf. These efforts collectively improve end-to-end data analysis workflows, reduce onboarding friction, and enable scalable analysis for large astronomical datasets.

June 2025

11 Commits • 6 Features

Jun 1, 2025

June 2025 — Focused on delivering practical, reproducible tutorials and improving onboarding for LSDB users. Key features delivered include an end-to-end Time Series Tutorial with loading, cleaning, analyzing, and visualizing time series data; introduction of Lomb-Scargle periodograms; and support for filtering, median magnitudes, and identifying periodic signals. A new Rubin DP1 Data Access Tutorial guides access to Rubin DP1 data on the Rubin Science Platform, prep of RSP containers, and ensures correct lsdb version. Enhanced Crossmatching and Row Filtering tutorials provide step-by-step guidance, tooling demonstrations, and clearer learning objectives. Documentation and Getting Started improvements refined onboarding flows, updated screenshots and visuals, and stabilized rendering for reST cells with consistent terminology and links.

May 2025

11 Commits • 5 Features

May 1, 2025

May 2025 performance summary for lincc-frameworks/notebooks_lf and astronomy-commons/lsdb. Delivered key features for catalog data representation, partition-processing guidance, and more robust catalog access, while improving API clarity and developer docs. Highlights include: Data Thumbnails for Catalogs with local/remote approaches (HATS) to speed up data access; Documentation and examples for partition processing with Dask + tqdm; Dataset HTML representation showing loaded vs total columns to improve data visibility; Added validation to raise helpful errors when accessing unloaded catalog columns; API rename lsdb.read_hats to lsdb.open_catalog with a backward-compatible alias to improve clarity and maintainability.

April 2025

6 Commits • 4 Features

Apr 1, 2025

April 2025 monthly summary focused on delivering data exploration capabilities, storage optimization, and documentation across three repositories. Key features include HealpixDataset data preview and sampling utilities, partition visibility exposure, compression strategy benchmarking for Parquet and object_forced_source datasets, and improved documentation linking to a Parquet compression analysis notebook. Achievements drove faster data exploration, reduced storage footprint, and improved I/O performance, backed by robust testing and clear technical documentation.

March 2025

7 Commits • 5 Features

Mar 1, 2025

March 2025 performance summary: Delivered and improved data-demo capabilities across three repositories. In lincc-frameworks/notebooks_lf, migrated HATS Notebooks to public data sources with Gaia DR3 access and added execution time measurements to showcase performance, plus refinement to focus on brighter objects. In astronomy-commons/lsdb, improved Dask logging and warning handling (suppress dashboard port warnings, ensure critical messages display) and standardized cone search radius calculation; in lsst-sitcom/linccf, enhanced photometric stability notebook with a reduce() demonstration in NestedFrame and a new scatter plot for stability diagnostics. These changes improve demo clarity, reliability, and performance visibility for customers and collaborators.

February 2025

3 Commits • 2 Features

Feb 1, 2025

February 2025 monthly summary for lincc-frameworks/notebooks_lf: Delivered Gaia data filtering notebook demo with LSDB/HATS integration, supporting magnitude-based filtering on Gaia data, data reading, applying magnitude and spatial filters, saving filtered data in HATS format, and updating properties for lazy loading. The notebook now displays computation results as a formatted HTML table (gaia_dr3) and demonstrates end-to-end data exploration. Implemented in-memory data processing pipeline to remove intermediate file I/O, with notebook execution counts and timing metrics updated to reflect the in-memory approach, speeding up iterations and reducing disk usage.

January 2025

2 Commits • 1 Features

Jan 1, 2025

January 2025 monthly summary for lsst-sitcom/linccf: Delivered a notebook workflow to identify wrongly classified supernovae by cross-matching catalogs from TNS and ZTF, including data loading, filtering, cross-matching preparation, and preliminary catalog statistics. Implemented two commits: c1153d925508f16a8a34e0812c2d23a063bb87b6 and 9c06233bedfcb2d6577739db8f117b742460c5a3.

December 2024

7 Commits • 3 Features

Dec 1, 2024

December 2024 performance summary: Delivered robust data import enhancements, stabilized batch processing, and improved code quality across notebooks_lf, hats-import, and hats. Focused on delivering business value through safer data ingestion, scalable batch creation, and maintainable pipelines, supported by targeted tests and documentation. Resulting impact includes faster and more reliable data imports, safeguarded catalogs, and reduced risk of interruptions in batch workflows.

November 2024

10 Commits • 4 Features

Nov 1, 2024

November 2024 monthly summary for lincc-frameworks focusing on delivering robust nested data capabilities, reliability improvements, and practical demonstrations for business impact. The work emphasizes performance-friendly data processing, correctness for complex nested schemas, and developer-friendly tooling in notebooks and tests.

October 2024

8 Commits • 2 Features

Oct 1, 2024

Oct 2024 monthly summary: Across astronomy-commons/lsdb and lincc-frameworks/nested-pandas, delivered tangible business value by improving data onboarding, reliability, and test coverage, while modernizing utility code and refining data-handling workflows.

Activity

Loading activity data...

Quality Metrics

Correctness91.4%
Maintainability90.4%
Architecture87.6%
Performance87.0%
AI Usage20.4%

Skills & Technologies

Programming Languages

JSONJupyter NotebookMarkdownPythonRSTShellTOMLYAMLipynbpython

Technical Skills

API DesignAPI DevelopmentAST ParsingAWSAstronomyAstronomy Data AnalysisAstronomy Data ProcessingAstronomy LibrariesAstrophysicsAstropyBackend DevelopmentBatch ProcessingBig DataCI/CDClass Methods

Repositories Contributed To

6 repos

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

astronomy-commons/lsdb

Oct 2024 Oct 2025
8 Months active

Languages Used

JSONJupyter NotebookpythonrstPythonreStructuredTextRSTipynb

Technical Skills

DocumentationJupyter NotebookCode FormattingDaskData EngineeringDistributed Computing

lincc-frameworks/notebooks_lf

Nov 2024 Oct 2025
8 Months active

Languages Used

Jupyter NotebookPythonMarkdownShell

Technical Skills

Data AnalysisJupyter NotebooksNested Data StructuresPandasBatch ProcessingBig Data

lincc-frameworks/nested-pandas

Oct 2024 Oct 2025
5 Months active

Languages Used

Python

Technical Skills

Code ClarityCode RefactoringCode ReviewData AnalysisDataFramesObject-Oriented Programming

lsst-sitcom/linccf

Jan 2025 Oct 2025
7 Months active

Languages Used

Jupyter NotebookPythonShell

Technical Skills

AstronomyAstronomy Data ProcessingCross-matchingDaskData AnalysisData Cataloging

astronomy-commons/hats-import

Dec 2024 Oct 2025
2 Months active

Languages Used

PythonTOMLYAML

Technical Skills

Backend DevelopmentCode FormattingCode RefactoringData EngineeringPylintPython

astronomy-commons/hats

Dec 2024 Dec 2024
1 Month active

Languages Used

Python

Technical Skills

Astronomy LibrariesNumerical ComputingUnit Testing

Generated by Exceeds AIThis report is designed for sharing and indexing