edX is an amazing tool to practice code, but also to earn certificates. edX is a non-profit online learning platform that was founded by Harvard University and MIT in 2012. According to their history, it has partnered with universities, organizations, and institutions globally to create a network of educational resources. edX offers paid courses with the option to earn a certificate or credential upon completion; however, you can take the entire course without the certification and start building your portfolio.
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