A developer observes that users are experiencing sporadic outages when attempting to load a web application service, receiving an unexpected 'Service Unavailable' message. This coincides with the recent rollout of new features. What initial action should the developer take to start diagnosing the root cause of the service disruptions?
Immediately initiate horizontal scaling action to increase the compute capacity available for the service.
Revert the web application service to a previous stable version that existed before the new feature rollout.
Examine the service's operational dashboard for system health and recent events that could indicate deployment-related issues.
Conduct a line-by-line review of the new features' codebase for potential syntactic or logical errors.