· Proficient understanding of web markup, HTML5, CSS3, JavaScript (ES5, ES6), jQuery · front-end frameworks: Foundation, Bootstrap, Materialize · HTML5 semantic layout, W3C valid · knowledge and experience in responsive and adaptive web design · understanding of cross-browser compatibility issues and ways to work · strong knowledge of web standards · understanding of UI/UX patterns and usability principles · creating and supporting JavaScript/jQuery plugins · experience with designs in Sketch and Photoshop for translation to markup · versioning tools Git, SVN, GitHub, Gitlab, Bitbucket · intermediate knowledge of programming languages (C#, PHP, Classic ASP) · up to date with emerging technologies and trends in the field · CSS pre-processors: LESS, SASS · using a task runners Gulp, Bundler, Webpack · website optimization using YSlow, GTmetrix, Google PageSpeed Insights · using code formatting methodologies OOCSS, BEM.