I'm most familiar with the Java version; this is from the docs:
https://jqwik.net/docs/current/user-guide.html#customized-pa...
Yes, of course you do have to define some patterns, but you can do that for arbitrary types and the internal randomizer takes care of the rest. You could have multiple cases, say: one that's fully random, one where you have some integers, one where you have strings, etc.