The September 2025 edition of the ClickHouse newsletter highlights various updates and events, including a detailed exploration by Tom Schreiber on scaling GROUP BY operations across thousands of cores for ultra-fast aggregations. The release of a new Parquet reader promises significant performance improvements, while Airbyte has introduced a first-class ClickHouse connector that enhances data loading efficiency. Featured community member Gaurav Sen is recognized for his educational contributions on ClickHouse's applications in AI and system design. The newsletter also outlines numerous global events, meetups, and training sessions, emphasizing ClickHouse's expanding community and ecosystem. Additionally, articles discuss common user mistakes, Laminar's innovative use of ClickHouse for AI observability, and various technical insights into leveraging ClickHouse for advanced data engineering tasks.