Mat Marquis is an independent consultant and front-end specialist with 15 years’ experience making websites that reliably reach every user, regardless of device, connection, or assistive technology. He focuses on inclusive web development—combining audits, hands-on remediation, and cultural change to embed accessibility, performance, and responsive practices into teams. His open-source contributions include work on high-profile projects like The COVID Tracking Project website, Picturefill, and jQuery Mobile, where he improved accessibility, responsive images, and cross-browser behavior. Previously he led inclusive web offerings at Bocoup and helped establish responsive design practices at Filament Group while working on the Boston Globe project. Based in Medford, MA, he blends pragmatic front-end engineering with CMS and build-system expertise (Netlify CMS, service workers, RSS) to deliver durable results. Colleagues rely on him not just to fix problems, but to leave teams with workflows and habits that sustain accessibility long-term.
A responsive image polyfill for <picture>, srcset, sizes, and more
Role in this project:
Front-end Developer
Contributions:5 releases, 193 commits, 14 PRs in 1 year 5 months
Contributions summary:Mat primarily contributed to the Picturefill project by modifying and improving the JavaScript code to enhance the functionality of the responsive images polyfill. Their commits focused on refining the parsing of the `srcset` attribute, ensuring correct image selection based on the viewport size, and adding various test cases to ensure that the functionality works as expected. The user implemented changes to optimize caching and introduced specific checks to address edge cases related to the `sizes` attribute and its interaction with native `srcset` behavior in different browsers.
Contributions summary:Mat primarily focused on improving the jQuery Mobile Framework's user interface components. Their work involved fixing bugs, such as icon visibility issues, and enhancing usability, particularly concerning input and select elements. The user also addressed accessibility issues, such as double-reading of button text in iOS VoiceOver. Their contributions included both CSS and JavaScript modifications to refine the styling and functionality of various UI widgets.
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Mat Marquis - Independent Consultant at Sole Proprietorship