Option logic and a pricing engine built around your actual pricing
Every configurator starts with the rules: which options are compatible with which, what happens when a customer picks a size that rules out a material, what triggers a surcharge. I map this against how you actually price the product today, whether that lives in a spreadsheet, an ERP, or in someone's head, and turn it into logic that updates the price live as options change, so the number on screen is always accurate, not a rough estimate.