We have developed application that fetch some data at the start, after that we use "lastmodified" to update all event.

Everything is ok until somebody will delete record - the record disapear in CRM, and there is no any information for API that there is no 4record. It force us to fetch all data once again. Maybe you can leave deleted records with status indicated that record has been deleter for a while, to give application opportunity to notice delation, and meybe after hour you can make record to disaper.

Or meybe there is possibility to fetch data from trash to check if some records were deleted?