Azure Event Grid is an event distribution tool that allows connecting external and Azure data sources with external and Azure data consumers, enabling the building of event-driven architectures. However, it lacks complex in-flight processing and has limited data storage, requiring additional tools for these features. Hookdeck is a comprehensive event gateway solution that ingests events over HTTP, offers complex in-flight processing, and can deliver to any HTTP destination. Amazon EventBridge is a point-to-point event gateway with simple in-flight processing but more complex integrations. Google Eventarc integrates mainly with other Google services and lacks direct integrations with external targets. Confluent Kafka is a powerful but complex platform that requires up-front planning and ongoing maintenance, offering rich ecosystem integrations and SQL/Java processing capabilities. When choosing an event gateway, consider the setup time, compatibility with producers and consumers, feature set, observability, failure handling, and recovery mechanisms.