One important breakthrough of optimality theory involves the formal analysis of the functional unity of phonological processes. Rule-based theories have no formal means of accounting for why diverse processes in a single language may conspire to have output forms meet a specific phonological shape or characteristic. I will illustrate how optimality theory can account for a functional conspiracy by considering in detail syllable contact phenomena in Korean. While the account of functional conspiracies is one of the major analytical achievements of optimality theory, there are, nonetheless, analytical challenges confronting it. I briefly touch on two such challenges, one concerning a specific prediction regarding blocking segments in harmony systems and the other concerning the analysis of phonological opacity. The overall conclusion of this article is that while optimality theory offers analytic insight and does make specific empirical predictions, the analysis of phonological opacity remains a challenge to the theory.