Figure 9.1. The core functionality of ActionBazaar. Sellers post items into searchable and navigable categories.
Bidders bid on items, and the highest bid wins.
• Sellers post items on ActionBazaar.
• Items are organized into searchable and navigable categories.
• Bidders place bids on items.
• The highest bidder wins.
Looking at these activities, you can pick out the domain objects by scanning the list of
activities and looking for nouns: seller, item, category, bidder, bid, and order. Your goal
is to identify the domain objects or entities you want to persist in the database. In the
real world, finding domain objects usually involves hours of work and numerous iterations
spent analyzing the business problem. You'll make the initial diagram by randomly throw-