While marketing-related notifications are often handled by marketing automation platforms, engineering teams require notification infrastructure that is designed for automated product-driven notifications. This might be a simple SMS password reset notification or new user onboarding email sequence. Or it may be a more complex notification tied to a feature of the application, such as an approval request sequence. The infrastructure required to handle these notifications is extensive and involves logic to trigger on an event, follow a specific workflow, personalize content, comply with guidelines, respect user preference, and work intelligently across channels. Notification APIs solve this problem by providing a combination of backend infrastructure and both server- and client-side SDKs that enable developers to build notifications in web and mobile apps. These APIs offer features such as multi-channel send, delivery status awareness across channels, automations, template management, central logs and reporting, user preferences, and internationalization. By leveraging notification APIs, developers can save time on building these features without sacrificing the end users' experience or creating technical debt. Notification APIs are typically used for transactional notifications but are increasingly being used for marketing notifications due to their ability to offer more personalized, event-driven marketing notifications that adhere to the user's behavior and preferences. The use of notification APIs offers numerous indirect benefits such as provider independence, consistency in notification formatting and delivery across various channels, simplification of integration and management of notification systems, and flexibility. Notification APIs have emerged as tools that enable developers to build product notification experiences that users love by offering a streamlined way to manage notification content, delivery logic, internationalization, compliance, and user preferences.