Use Azure Data Factory with a Copy Data activity to ingest the event stream and store it in Azure Blob Storage. Then, use a Data Flow activity to aggregate the data and load it into the Data Warehouse.

Use Azure Stream Analytics to ingest the event stream, apply the aggregation logic, and store the results in Azure Data Lake Storage Gen2. Then, use Azure Data Factory to load the aggregated data into the Data Warehouse.

Use Azure Event Hubs to capture the event stream, and then use Azure Functions to process the data in real-time and store the aggregated results in Azure Cosmos DB.

Use Azure Logic Apps to trigger a workflow for each event in the stream, and then use a custom connector to aggregate the data and store it in the Data Warehouse.