If you want to find out if someone is compatible with you, do any activity where you have to work together. This is true for business or personal relationships.
Simply ordering a pizza is a good indicator of whether you can get along with each other.
Does he want all meat, and you think meat is murder? Is she allergic to all your favorite toppings? Do you have to get two separate pizzas to both be content? This does not bode well for a harmonious relationship.
Try doing a jigsaw puzzle together. Does he try to work on the same area you are working on, getting in your way? Does she get jealous when you finish an area before her?
You both don’t have to do the same things or be exactly the same. That would be a little weird. But you do both have to work well together, encouraging each other and building each other up.
Relationships are a lot like three legged races. If you aren’t working together, you are going nowhere.