Domain-Driven Design in PHP

Introduction

If you've worked with e-commerce applications, it's likely you've faced bugs related to data inconsistencies in your database. For example, consider a shopping order with a total amount of $99.99, which doesn't match with the sum of the amounts of each line in the order, $89.99. Where did that extra $10 come from?

Or, consider a website that sells tickets for the cinema. There's a movie theater with 100 available seats, and after a successful movie promotion, everyone is on the website waiting for the tickets to become available for purchase. Once you open the sales, everything happens fast and you somehow end up selling 102 tickets. You may have specified that there are only 100 seats, but for some reason you exceeded that threshold. ...