We had a magento 2.3.0 multi-website shop and we use custom product import for shops. We use CLI script as a config for each shops and execute import with a common custom module handing few checkings. We read the a pre-defined column file and import to corresponding product attributes. Each shops crons are set on different timing(for example, for shop X we have "php importX.php" where we define basic configuration like website id, code,sku prefix etc). Now issue we have is some shops having around 3500 rows in the file and it's taking more than 7 hours to complete. Any advice on this really appreciated.