I know set theory has some very real world applications, like formulating a data query in set notation. Applying set transformations to it to get a more optimiz

I know set theory has some very real world applications, like formulating a data query in set notation. Applying set transformations to it to get a more optimized query and then transposing that to SQL to get a correct and performant sql query. How do order theory and category theory have practical effects on computing? At university we learn this to explain how RSA works, but besides having funky properties that are nice for implementing asymmetrical encryption, it left me confused about their use in everyday computing.