
Jesse Greenberg developed and maintained interactive science simulations across repositories such as membrane-transport, sun, and greenhouse-effect, focusing on accessibility, localization, and UI reliability. He engineered robust ARIA and screen reader support, modularized codebases with TypeScript and Fluent for safer internationalization, and implemented features like keyboard navigation, voicing, and dynamic UI feedback. Jesse’s work included refactoring legacy JavaScript to modern TypeScript, optimizing rendering performance, and standardizing accessibility patterns to improve usability for assistive technologies. By integrating automated testing, documentation, and ESLint-driven code quality, he delivered maintainable, user-focused solutions that enhanced both developer productivity and end-user experience.

October 2025 monthly summary: Focused on expanding accessibility, standardizing UI accessibility patterns, and stabilizing development across multiple repos. Delivered key features, improved keyboard navigation, and enhanced screen-reader reliability; laid groundwork for broader UX improvements and developer consistency across phet-info, sun, build-an-atom, and related projects.
October 2025 monthly summary: Focused on expanding accessibility, standardizing UI accessibility patterns, and stabilizing development across multiple repos. Delivered key features, improved keyboard navigation, and enhanced screen-reader reliability; laid groundwork for broader UX improvements and developer consistency across phet-info, sun, build-an-atom, and related projects.
September 2025 monthly summary: This month focused on stabilizing CI and test reliability, delivering high-impact feature work, and advancing code health through accessibility improvements and TypeScript migrations across multiple repositories. Key outcomes include stabilizing phetio compare tests in Babel to reduce CI flakiness, delivering significant membrane-transport feature work and refactors, and advancing accessibility and VOICE support across Sun, Ph-scale, phet-info, and membrane-transport. The work also continued the TypeScript migration in greenhouse-effect, setting the stage for safer, long-term maintenance. The release pipeline was prepared with a 1.0.0-dev.28 bump to support ongoing development and testing.
September 2025 monthly summary: This month focused on stabilizing CI and test reliability, delivering high-impact feature work, and advancing code health through accessibility improvements and TypeScript migrations across multiple repositories. Key outcomes include stabilizing phetio compare tests in Babel to reduce CI flakiness, delivering significant membrane-transport feature work and refactors, and advancing accessibility and VOICE support across Sun, Ph-scale, phet-info, and membrane-transport. The work also continued the TypeScript migration in greenhouse-effect, setting the stage for safer, long-term maintenance. The release pipeline was prepared with a 1.0.0-dev.28 bump to support ongoing development and testing.
August 2025 highlights across the membrane-transport family and related repos. Delivered major release readiness with two dev-version bumps (1.0.0-dev.21 and 1.0.0-dev.23) that updated dev HTML and dependencies, enabling stable testing and faster iteration. Implemented comprehensive accessibility and Voicing improvements (full Voicing support, ReadingBlock usage, and voicing for mouse input) with internationalization considerations. Enhanced keyboard navigation and UI polish (WASD support for SoluteControl, keyboard help improvements, stronger interaction hints, and UI verbosity reductions). Strengthened code quality and maintainability through modulify refactors, TypeScript migrations (Greenhouse Effect), and extensive documentation/JSDoc updates. Addressed several stability bugs (disable SoluteControl interactive highlight, input handling simplifications, play/pause/ligand mode state fixes, and general lint/doc hygiene). Collectively these changes increase business value by improving accessibility, reliability, and developer productivity while accelerating user-focused feedback cycles.
August 2025 highlights across the membrane-transport family and related repos. Delivered major release readiness with two dev-version bumps (1.0.0-dev.21 and 1.0.0-dev.23) that updated dev HTML and dependencies, enabling stable testing and faster iteration. Implemented comprehensive accessibility and Voicing improvements (full Voicing support, ReadingBlock usage, and voicing for mouse input) with internationalization considerations. Enhanced keyboard navigation and UI polish (WASD support for SoluteControl, keyboard help improvements, stronger interaction hints, and UI verbosity reductions). Strengthened code quality and maintainability through modulify refactors, TypeScript migrations (Greenhouse Effect), and extensive documentation/JSDoc updates. Addressed several stability bugs (disable SoluteControl interactive highlight, input handling simplifications, play/pause/ligand mode state fixes, and general lint/doc hygiene). Collectively these changes increase business value by improving accessibility, reliability, and developer productivity while accelerating user-focused feedback cycles.
July 2025 performance highlights across seven+ repositories, emphasizing accessibility, core terminology alignment, UI/UX refinements, hotkey handling, and release readiness. The team delivered cross-repo improvements that enhance accessibility compliance, reduce ongoing maintenance burdens, and position projects for stable releases.
July 2025 performance highlights across seven+ repositories, emphasizing accessibility, core terminology alignment, UI/UX refinements, hotkey handling, and release readiness. The team delivered cross-repo improvements that enhance accessibility compliance, reduce ongoing maintenance burdens, and position projects for stable releases.
June 2025 performance highlights: Delivered a substantial set of features, reliability fixes, and architectural improvements across membrane-transport and related projects. Key feature work includes glucose absorption bar chart visualization with color change and full-fill behavior, stereo option labels localization, particle rendering optimization to reduce pixelation, and broad UI/UX enhancements driving clearer feedback and accessibility. We modularized the codebase with FluentVariable, added notes on concentration gradients, and implemented screen-summary-driven model Properties. Major stability and quality fixes include resetting particle opacity on preferences changes, formatting cleanups, removing unused components, and bug fixes around protein/solutes lifecycle. Accessibility and Voicing improvements were advanced with context responses, tier-1 adoption, and configurable voicing behavior. Build and tooling were upgraded with version 1.0.0-dev.12, updated dev HTML and dependencies, and automation for modulify after YAML changes. Across membranes-transport, phet-info, perennial, sun, and babel, these changes boost user experience, localization, accessibility, and developer productivity, delivering measurable business value through improved UI reliability, faster iteration cycles, and clearer, accessible feedback for assistive technologies.
June 2025 performance highlights: Delivered a substantial set of features, reliability fixes, and architectural improvements across membrane-transport and related projects. Key feature work includes glucose absorption bar chart visualization with color change and full-fill behavior, stereo option labels localization, particle rendering optimization to reduce pixelation, and broad UI/UX enhancements driving clearer feedback and accessibility. We modularized the codebase with FluentVariable, added notes on concentration gradients, and implemented screen-summary-driven model Properties. Major stability and quality fixes include resetting particle opacity on preferences changes, formatting cleanups, removing unused components, and bug fixes around protein/solutes lifecycle. Accessibility and Voicing improvements were advanced with context responses, tier-1 adoption, and configurable voicing behavior. Build and tooling were upgraded with version 1.0.0-dev.12, updated dev HTML and dependencies, and automation for modulify after YAML changes. Across membranes-transport, phet-info, perennial, sun, and babel, these changes boost user experience, localization, accessibility, and developer productivity, delivering measurable business value through improved UI reliability, faster iteration cycles, and clearer, accessible feedback for assistive technologies.
May 2025 monthly highlights focused on delivering accessible, robust, and maintainable improvements across membranes-transport and related projects, with a strong emphasis on business value, user experience, and developer productivity.
May 2025 monthly highlights focused on delivering accessible, robust, and maintainable improvements across membranes-transport and related projects, with a strong emphasis on business value, user experience, and developer productivity.
April 2025 performance summary: Delivered cross-repo accessibility enhancements, screen reader voicing improvements, and targeted UI feedback across six repositories (sun, membrane-transport, phet-info, greenhouse-effect, models-of-the-hydrogen-atom, and build-an-atom). Key work focused on standardizing accessible headings, ARIA semantics for dialogs and radio groups, and improving keyboard/screen reader interactions, complemented by substantial code quality and maintainability improvements. Key features and improvements: - sun: Accessibility improvements across dialogs, radio button groups, and headings; enhanced voicing for radio groups; code-quality fix to break circular dependencies via import type. - membrane-transport: Added release sound for dropping proteins; ligand dragging bug fix and ligand-binding sounds; narrowed sodium-potassium pump filter; progress on protein description/voicing; extensive refactors (TransportProtein, image usage, model width transforms, state-change routing via link); API and documentation notes for accessibility and features; added activity-level description groundwork. - phet-info: Tier 1 Description quick-start guide enhancements and Tier 1 Voicing quick-start guide updates. - greenhouse-effect: Accessible headings standardization across UI components. - models-of-the-hydrogen-atom: Accessible dialog improvements using accessibleHeading and accessibleParagraph patterns. - build-an-atom: Accessible headings refactor for AtomScreenView. Overall impact: - Improved accessibility compliance and screen reader semantics across the platform, leading to easier adoption by users relying on assistive tech. - Richer UX feedback through audio cues and voicing, improving task completion reliability for interactive simulations. - A cleaner, more maintainable codebase with modular refactors and safer imports, enabling faster future iterations and reduced regression risk. Technologies/skills demonstrated: - Accessibility: ARIA semantics, accessibleHeading, accessibleParagraph, and role handling. - Voicing and screen reader UX: hint responses, initial focus behavior, and mouse-initiated voicing. - Audio feedback integration: release sounds, ligand-binding sounds, boundary sounds. - Code quality and architecture: import type usage to break circular dependencies, refactors into TransportProtein, state-change updates via Link, direct Image usage, and naming conventions. - Documentation and onboarding: quick-start and guidance updates for Tier 1 accessibility features.
April 2025 performance summary: Delivered cross-repo accessibility enhancements, screen reader voicing improvements, and targeted UI feedback across six repositories (sun, membrane-transport, phet-info, greenhouse-effect, models-of-the-hydrogen-atom, and build-an-atom). Key work focused on standardizing accessible headings, ARIA semantics for dialogs and radio groups, and improving keyboard/screen reader interactions, complemented by substantial code quality and maintainability improvements. Key features and improvements: - sun: Accessibility improvements across dialogs, radio button groups, and headings; enhanced voicing for radio groups; code-quality fix to break circular dependencies via import type. - membrane-transport: Added release sound for dropping proteins; ligand dragging bug fix and ligand-binding sounds; narrowed sodium-potassium pump filter; progress on protein description/voicing; extensive refactors (TransportProtein, image usage, model width transforms, state-change routing via link); API and documentation notes for accessibility and features; added activity-level description groundwork. - phet-info: Tier 1 Description quick-start guide enhancements and Tier 1 Voicing quick-start guide updates. - greenhouse-effect: Accessible headings standardization across UI components. - models-of-the-hydrogen-atom: Accessible dialog improvements using accessibleHeading and accessibleParagraph patterns. - build-an-atom: Accessible headings refactor for AtomScreenView. Overall impact: - Improved accessibility compliance and screen reader semantics across the platform, leading to easier adoption by users relying on assistive tech. - Richer UX feedback through audio cues and voicing, improving task completion reliability for interactive simulations. - A cleaner, more maintainable codebase with modular refactors and safer imports, enabling faster future iterations and reduced regression risk. Technologies/skills demonstrated: - Accessibility: ARIA semantics, accessibleHeading, accessibleParagraph, and role handling. - Voicing and screen reader UX: hint responses, initial focus behavior, and mouse-initiated voicing. - Audio feedback integration: release sounds, ligand-binding sounds, boundary sounds. - Code quality and architecture: import type usage to break circular dependencies, refactors into TransportProtein, state-change updates via Link, direct Image usage, and naming conventions. - Documentation and onboarding: quick-start and guidance updates for Tier 1 accessibility features.
March 2025 performance snapshot: delivered substantial feature work, stability enhancements, and accessibility/localization groundwork across multiple repos with direct business impact on realism, reliability, and maintainability. Key outcomes include:
March 2025 performance snapshot: delivered substantial feature work, stability enhancements, and accessibility/localization groundwork across multiple repos with direct business impact on realism, reliability, and maintainability. Key outcomes include:
February 2025 performance snapshot: Delivered cross-repo feature work, bug fixes, and foundational architecture across membrane-transport, greenhouse-effect, perennial, phet-info, sun, hydrogen-atom, and ph-scale. Highlights include UI/UX and accessibility improvements, model/IO refactors, and groundwork for solute flux and drag interactions, with a strong emphasis on business value through improved usability, reliability, and localization readiness. Key features delivered this month include: Solute controls UI enhancements in membrane-transport (added tandems to voltage controls, object response for solute controls, and ions renaming); default solute population and solute bar chart groundwork; solute flux state modeling and IO refactor; rename Solute to Particle and reuse Particle code for Ligands; initial dragging ligands groundwork; accessibility naming improvements (helpText to accessibleHelpText) across multiple repos; PhET-iO notes; and related GroupSort/GroupSelect interaction work. In addition, a broad set of maintenance and cleanup tasks across repos improved stability and hygiene (TODO cleanup, removal of obsolete accessibility files, and repo cleanup). Major changes across repositories (highlights): - membrane-transport: solute UI and nomenclature enhancements; flux/model refactor; removal/focus and dragging groundwork; accessibility naming updates; UI/UX responsiveness improvements. - greenhouse-effect: localization consistency updates and accessibility naming improvements, plus accessibility artifacts cleanup. - perennial: dev environment cleanup and text normalization standards. - phet-info: accessibility and developer workflow documentation improvements. - sun: accessibility enhancements, internationalization structuring, and cleanup of deprecated assets. - hydrogen-atom: accessibility improvements and cleanup of unused accessibility view. - ph-scale: removal of obsolete auto-generated accessibility view.
February 2025 performance snapshot: Delivered cross-repo feature work, bug fixes, and foundational architecture across membrane-transport, greenhouse-effect, perennial, phet-info, sun, hydrogen-atom, and ph-scale. Highlights include UI/UX and accessibility improvements, model/IO refactors, and groundwork for solute flux and drag interactions, with a strong emphasis on business value through improved usability, reliability, and localization readiness. Key features delivered this month include: Solute controls UI enhancements in membrane-transport (added tandems to voltage controls, object response for solute controls, and ions renaming); default solute population and solute bar chart groundwork; solute flux state modeling and IO refactor; rename Solute to Particle and reuse Particle code for Ligands; initial dragging ligands groundwork; accessibility naming improvements (helpText to accessibleHelpText) across multiple repos; PhET-iO notes; and related GroupSort/GroupSelect interaction work. In addition, a broad set of maintenance and cleanup tasks across repos improved stability and hygiene (TODO cleanup, removal of obsolete accessibility files, and repo cleanup). Major changes across repositories (highlights): - membrane-transport: solute UI and nomenclature enhancements; flux/model refactor; removal/focus and dragging groundwork; accessibility naming updates; UI/UX responsiveness improvements. - greenhouse-effect: localization consistency updates and accessibility naming improvements, plus accessibility artifacts cleanup. - perennial: dev environment cleanup and text normalization standards. - phet-info: accessibility and developer workflow documentation improvements. - sun: accessibility enhancements, internationalization structuring, and cleanup of deprecated assets. - hydrogen-atom: accessibility improvements and cleanup of unused accessibility view. - ph-scale: removal of obsolete auto-generated accessibility view.
January 2025: Cross-repo progress focused on accessibility, Voicing readiness, and localization, with build-time modularization and performance improvements across Sun, Hydrogen Atom, Greenhouse Effect, and related projects. Delivered UI accessibility enhancements, Voicing support across core input components, and API refactors to prepare future Voicing features, while consolidating localization tooling and cleaning up the codebase to improve maintainability and release velocity. These efforts enhance user reach, reduce localization friction, and lay groundwork for richer auditory experiences.
January 2025: Cross-repo progress focused on accessibility, Voicing readiness, and localization, with build-time modularization and performance improvements across Sun, Hydrogen Atom, Greenhouse Effect, and related projects. Delivered UI accessibility enhancements, Voicing support across core input components, and API refactors to prepare future Voicing features, while consolidating localization tooling and cleaning up the codebase to improve maintainability and release velocity. These efforts enhance user reach, reduce localization friction, and lay groundwork for richer auditory experiences.
December 2024 monthly summary focusing on localization, UI improvements, and maintainability across multiple repositories. Delivered multilingual translations (French, Spanish, Arabic) and Fluent localization integration, centralized string management, and UI layout improvements. Achieved broader international reach, improved accessibility, reduced maintenance burden via centralized resources, and simplified loading by removing an unnecessary preload. Demonstrated strong collaboration across repos (greenhouse-effect, perennial, babel, sun) and solidification of localization workflows.
December 2024 monthly summary focusing on localization, UI improvements, and maintainability across multiple repositories. Delivered multilingual translations (French, Spanish, Arabic) and Fluent localization integration, centralized string management, and UI layout improvements. Achieved broader international reach, improved accessibility, reduced maintenance burden via centralized resources, and simplified loading by removing an unnecessary preload. Demonstrated strong collaboration across repos (greenhouse-effect, perennial, babel, sun) and solidification of localization workflows.
November 2024 monthly summary focused on strengthening cross-repo merge discipline, modernizing the codebase with Fluent/TypeScript, and expanding accessibility and localization across key simulations. Deliverables include a safer multi-repo merge workflow for perennial, enhanced brancher tooling with status checks and safe merging, Fluent/TypeScript modernization across the repo suite, and comprehensive accessibility improvements with ARIA labeling across models-of-the-hydrogen-atom and related simulations, plus locale handling fixes for accessibility views in ph-scale. These changes reduce release risk, improve reliability, and enhance inclusive, multilingual user experiences, aligning with business goals of reliability, accessibility, and international reach.
November 2024 monthly summary focused on strengthening cross-repo merge discipline, modernizing the codebase with Fluent/TypeScript, and expanding accessibility and localization across key simulations. Deliverables include a safer multi-repo merge workflow for perennial, enhanced brancher tooling with status checks and safe merging, Fluent/TypeScript modernization across the repo suite, and comprehensive accessibility improvements with ARIA labeling across models-of-the-hydrogen-atom and related simulations, plus locale handling fixes for accessibility views in ph-scale. These changes reduce release risk, improve reliability, and enhance inclusive, multilingual user experiences, aligning with business goals of reliability, accessibility, and international reach.
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