Hi, While client uploads content into permanent temp file ngx worker doesn't process any requests until its finished. Its an issue in case of large files (GBs) uploading since number of parallel uploads are limited by number of workers. https://www.nginx.com/blog/thread-pools-boost-performance-9x/ advises to use aio_write: "At the moment, offloading to thread pools is implemented onby python - Nginx Mailing List - English