Learn Finnish: Kokemus yksilöityy kaikissa sovelluksissa, joita käytämme. - The experience becomes individualized in all the applications that we use.

It is formed from the noun yksilö (an individual). The automative suffix -öityä turns it into a verb of process. It means that the subject (kokemus) undergoes the change itself, translating to "becomes individualized" or "becomes personalized" without needing an active, external agent.

If the suffix is -öityä, why isn't the verb yksilööityä?

While the suffix is generally taught as -oitua or -öityä, when the base noun already ends in o or ö (like yksilö), you only add -itua or -ityä. This prevents the formation of awkward and unnatural vowel clusters.

Why is the relative pronoun joita in the partitive plural rather than the inessive plural (joissa) to match sovelluksissa?

A relative pronoun takes its number (plural) from the noun it refers to, but its case is dictated by its grammatical role in its own clause. Here, joita is the object of the verb käytämme (we use). The verb käyttää requires a partitive object, hence joita.

Could you do a quick refresher on how the ending for sovelluksissa is formed?