How to Answer API Integration in Salesforce

To design a scalable API integration between Salesforce and an external customer management system, I would first identify the key data fields that need to be synchronized, such as customer details and order histories. I would use Salesforce's REST API to facilitate this integration, ensuring that secure authentication mechanisms, like OAuth, are implemented. I would implement asynchronous processing using Salesforce's Queueable Apex to handle batch updates efficiently, minimizing the impact on system performance. Additionally, I would establish a monitoring system to log API responses and handle errors gracefully, ensuring data consistency between both systems. Testing will be crucial, especially to simulate high-load scenarios and validate data integrity post-sync.