Using middleware queuing and buffering is a solution that can handle errors during service outages by storing the messages in a queue until the service is available again. This way, Salesforce does not loseany data or encounter any failures when the service is down. Using @future jobld and custom scheduled apex process to retry failed service calls is not a good solution because it can consume a lot of governor limits and create a lot of duplicate records. Using Outbound Messaging to automatically retry failed service calls is also not a good solution because it has a limited number of retries and a fixed retry interval, which may not be sufficient for long service outages. Using Platform Event replayld and custom scheduled Apex process to retrieve missed events is not applicable for this scenario because Platform Events are used for event-driven integration, not for web-service integration. Reference: Salesforce Integration Architecture Designer Resource Guide, page 29-
30