Building a notification system for an MVP can drive engagement, enable user journeys based on asynchronous actions, and support time-sensitive operations. A simple notification system consists of key components such as notification triggers, decision logic, templating, and connections to messaging providers. By implementing these components, developers can send notifications via email APIs, create message templates using a templating "system", and make decisions on whether to notify users based on event parameters. When building an MVP-stage notification system, it's essential to consider features that drive metrics such as daily active users, exclude non-essential functionality, and prioritize polished experiences for a limited set of notifications, right timing, and reliability. Additionally, developers should avoid common pitfalls such as shortcuts that can become painful in the future, neglecting deliverability, and not considering multiple customer groups' experiences. By following these guidelines, developers can build an MVP notification system quickly and effectively.