Webhooks play a crucial role in facilitating real-time communication and data sharing between applications in SaaS integrations. They are triggered by relevant state changes within a system and are sent as HTTP POST requests to specified URLs, reducing the need for continuous querying of APIs. According to Justin Hipple, Co-founder and Chief Software Architect at Prismatic, an efficient webhook architecture should be lightweight and focus on key events, with the emission code being separate from database transactions to avoid performance issues. Utilizing a queue system like AWS SQS or other tools such as Kafka or RabbitMQ ensures reliable event delivery. Payloads should be uniformly structured, including necessary data fields, and security measures like HMAC can prevent unauthorized access. Handling failures can involve retry policies with exponential backoff or re-queuing events, with idempotency being important depending on the application type. Webhooks are advantageous for integrations as they are a widely accepted standard that keeps systems decoupled and minimizes resource-intensive API queries.