Principal technologist and open-source leader, now building and contributing to open-source AI, hands-on.

I've spent two decades at the intersection of technology, policy, and public service, including leading the U.S. federal government's Open Source Program Office (Code.gov). These days I'm going back to the code: learning modern AI from the source up and contributing to the open-source projects building it.

• Building a federal agentic AI practice by day, contributing to open-source AI by night.
• Going deep on the Model Context Protocol (MCP), agent frameworks, and AI gateways: the layer where LLM traffic meets API infrastructure.
• Shipping small, useful PRs (accessibility, docs, and bug fixes) across projects I actually use.

AI & LLM tooling

• OpenHands: an open-source platform for AI-driven software development agents.
• Aider: AI pair programming in the terminal.
• Lex (i.AI, UK AI Incubator): a UK legal API for AI agents and researchers.
• AnythingLLM: a self-hostable, all-in-one application for turning documents and content into context for any LLM, with agents and RAG built in.

Python & developer ecosystem

• Python Developer's Guide: the official guide to contributing to CPython itself, covering setup, workflow, and the standards the language is developed under.
• Furo: the Sphinx documentation theme behind the Python Developer's Guide, CPython's own documentation, and a large share of the Python ecosystem.

Government design systems

• USWDS: the U.S. Web Design System, helping federal agencies build fast, accessible, mobile-friendly websites.
• GOV.UK Design System: the front-end code behind UK government platforms and services.
• GC Design System (Canadian Digital Service): the web components behind Government of Canada digital services.
• GC Design System Docs (Canadian Digital Service): the bilingual documentation site teams use to adopt the GC Design System.
• Web Experience Toolkit (Government of Canada): the open-source library behind accessible, usable, and interoperable Government of Canada websites.

Public sector & open data

• code.gov (GSA): the U.S. federal government's open source code in support of M-16-21.
• repo-scaffolder (Digital Service at CMS): templates and command-line tools for creating U.S. federal open-source repositories that meet policy requirements.
• CKAN: the open-source data management system powering catalog.data.gov, open.canada.ca/data, and data.humdata.org.
• Datasette: an open source multi-tool for exploring and publishing data.
• government.github.com: the directory of government organizations using GitHub for open government work.
• BC Wallet (Government of B.C.): a mobile wallet for verifiable credentials.

Financial infrastructure

• Apache Fineract: the back-office UI for Apache Fineract, the open-source core banking platform.
• Architecture as Code (FINOS): a machine-readable, version-controlled way to define and manage software architecture.

API & cloud infrastructure

• Apache APISIX Dashboard: the dashboard for Apache APISIX, the cloud-native API and AI gateway.
• Apache ActiveMQ Artemis Console: the management console for Apache ActiveMQ Artemis, the high-performance open-source message broker.

• Government Open Source: An Analysis (repo): a census of the 1,079 government GitHub organizations on governments.yml: 75,638 public repos, how much is still maintained, and how much accepts outside contributions.

I use AI coding assistants to get up to speed on unfamiliar codebases quickly. I read, run, and take responsibility for everything I submit, and if a patch of mine is wrong, that's on me. Reviewer time is the scarcest resource in open source, and I try hard not to waste it.

• VP, Technology Solutions at HumanTouch, LLC: leading AI engineering and agentic-AI workflows on the CORASai platform in collaboration with federal agencies, carrying two decades of open-source and gov-tech leadership into the AI era
• Maryland Governor Appointment to the Council for Open Data: supporting the State Chief Data Officer (CDO) on implementation of SB0200/HB0262 by working with state agencies and local governments to meet the Governor's priorities
• Director, Code.gov: ran the federal Open Source Program Office (OSPO) and grew federal open-source participation from 45 to 7,000 repositories across 20 agencies. Brought the platform into Section 508 compliance and added automated accessibility testing to its CI pipeline
• The White House (Executive Office of the President): developed M-13-13 Open Data Policy Supplemental Guidance and implemented the President's Digital Strategy
• Contributor to federal open-source and AI policy, including the Federal Source Code Policy (codified into law as the SHARE IT Act in 2024) and OMB M-24-10
• GitHub Star, 2021-2024 · Fed100, 2019
• PhD, Public Administration and Public Affairs. Dissertation: An Organizational Analysis of Publishing the People's Code

• LinkedIn: linkedin.com/in/jrcastle

_{Learning in public, contributing to the open-source AI ecosystem one PR at a time.}