Content Management Systems (aka CMS)
Node.js
Cross-Browser Testing
Cross-Platform Testing
Unit Testing
Cross-Device Testing
Accessibility / WAI-ARIA
Search Engine Optimization (aka SEO)
Interaction or User Interface Design
User Experience
Usability
E-commerce Systems
Portal Systems
Wireframing
CSS Layout / Grids
DOM Manipulation (e.g., jQuery)
Mobile Web Performance
Load Testing
Performance Testing