Azure Functions can be configured to run on fixed schedules via timer triggers (https://docs.microsoft.com/en-us/azure/azure-functions/functions-bindings-timer

Azure Functions can be configured to run on fixed schedules via timer triggers (https://docs.microsoft.com/en-us/azure/azure-functions/functions-bindings-timer https://docs.microsoft.com/en-us/azure/azure-functions/funct...), so I’m guessing they set theirs to run every API timeout interval + max amount of time they could request tweets before getting rate limited. Their Cosmos DB instance could then be set up to track how many tweets they had gotten through on each function run.