CogDev is my personal company which I have operated informally for many years before registering it as a business several years ago.
I have completed many freelance projects using a wide variety of languages and skillsets, from PHP and MySQL to talking to hardware using Python APIs. As a solo freelancer, I am responsible for not only front- and backend development, but also for "softer" areas of project management such as requirements-gathering and customer support.
In addition to projects for companies, I also maintain a personal project under the Cognitive Development name as a breeding ground and testbed for new ideas I'd like to try out. At its peak, this project received over 10 million page views and around 26,000 unique visitors monthly.