Scott Jehl is a US front-end developer (formerly at Filament Group) and one of the most cited voices on web performance, progressive enhancement, and the responsive-design discipline. He has authored multiple practical books on these topics including Responsible Responsive Design and Web Components Demystified.
His CourseFlix listing carries Web Components Demystified — covering the platform-native Web Components specification (Custom Elements, Shadow DOM, slots, ES Modules) as a framework-independent UI primitive that survives every front-end framework change.
Material is paid and aimed at front-end developers picking up Web Components for framework-independent UI work. For broader content, see CourseFlix's Frontend System Design category page.