Udacity is one of the best platforms to hone job-specific skills in various computer science subjects. Courses are led by experts and come with relevant assignments that you can use when applying for a job or promotion. The best part is that Udacity offers more than 200 courses entirely for free. Additionally, you can try out the paid programs for either two days (for the U.S.) or 14 days (for the UK and EU) by taking advantage of the company’s refund policy. Finally, some Udacity partners offer scholarships for certain programs, which can cover part or all of the nanodegree’s cost.