Design pattern for rating engine

can you please point to any good design patterns/frameworks to code the following system, preferably in java/scala/spring : A a kind of rating engine that will take about 100+ parameters with a range of options and do lots of computation/business logic to come up with some rating numbers. The business variables are also subject to change as well as business rules. I have seen similar engines in insurance and banking sector but never coded one. Thanks a lot #designpatterns