With Yandex. Practicum you just start to do things. Education process follows the rule "Less theory, more practice" and this is great! I already finished 1/3 of the Data Science program and wrote 4 projects with real review process (by human). I'm recommending the platform if you don't know from what to start. Practicum gives you a full view of the day-to-day tasks, what you will do on this job title and how to do a decision making. In other words you will prepare to reality of a speciality.