Learn Finnish: Tästä opiskelijasta tulee kokoaikainen ohjelmoija. - This student will become a full-time programmer.

This sentence uses the specific transformation construction you are learning in this lesson. When someone or something turns into a profession or a new state, Finnish expresses it as 'From X comes Y'. Because of this, the original person (this student) is put into the elative case (-sta), which literally translates to 'out of'.

Why is the result, kokoaikainen ohjelmoija, in the nominative case here? Doesn't becoming something usually require the translative case (-ksi)?

That is a very common B1 mix-up! If you start with a normal nominative subject, you do use the translative for the result (for example, Hän tulee iloiseksi meaning 'He becomes happy'). However, when you use the 'From X comes Y' structure with the elative case (Tästä opiskelijasta), the grammatical rule changes and the result must be in the nominative case.

If the sentence were about multiple students becoming programmers, would the verb tulee become plural?

No, the verb in this specific elative construction is always frozen in the third-person singular (tulee). Even if you were to say 'These students will become programmers' (Näistä opiskelijoista tulee ohjelmoijia), the verb remains exactly the same.

How is the adjective kokoaikainen formed?