The news service needs to store link events for each user. The link service knows when links are added, updated, or deleted by different users. One approach to solve this problem is to add another API to the news service and have the link service invoke this API and notify the news service for each relevant event. However, this approach creates a tight coupling between the link service and the news service. The link service doesn't really care about the news service since it doesn't need anything from it. Instead, let's go for a loosely-coupled solution. The link service will just send events to a general-purpose message queue service. Then, independently, the news service will subscribe to receive messages from that messages queue. There are several benefits to this approach, as follows:
- No need for more complicated...