Front End
HTML5, CSS3, Javascript. Bootstrap 3 & 4, Bulma.io.
Commercial Open Source
I have done a lot with commercial open source software such as Drupal, Wordpress, Aegir and now learning Phoenix, Elixir and Erlang.
Responsive & Progressive, Mobile & Web Apps
Using HTML5, CSS3 and Javascript and the Bootstrap 4, Bulma.io and jQuery frameworks for mobile-first web application development.
Back End
MySql, Postgres databases, Erlang and Elixir, Ubuntu Linux & Ansible configuration management.
Cloud & Bare-Metal
Rackspace, Amazon Web Services, Linode, Vultr, Digital Ocean, OVH cloud and bare-metal servers.
Functional Programming
PHP and Elixir functional programming.