Coding schools in San Francisco are easy to come by, but Holberton School sets itself apart by not charging tuition. Instead, it has graduates give back 17% of their salaries or internship pay for the first three years after graduation. It also doesn't employ formal teachers or give lectures, most of the curriculum is based around students working on specific projects and teaching each other. Through this tuition-free model, the school is hoping to bring more diversity into the tech industry, and educate those who wouldn't otherwise be able to get tech training. Some of its students have already been hired by companies like Google, LinkedIn, and NASA.