Configuring alerts in MongoDB Atlas is crucial to ensure proactive maintenance and minimize downtime for applications. The platform provides default alerts but also allows customizing monitoring policies, change notifications, performance indications, and notification channels such as Slack or PagerDuty. By setting up alerts for specific conditions like disk space, connections, or performance limits, teams can proactively scale their database environment, reduce costs, and provide a better experience for users. MongoDB Atlas offers various outbound notification options, including email, SMS, and chat notifications via HipChat/Slack/Flowdock, to ensure team members are informed about potential issues or changes in the cluster.