Currently around half of the execution time in this endpoint is spent on checking the latest last updated date of an orderable to use with If-Modified-Since header. This is because all of the orderables matching the search criteria are retrieved and sorted by the updated date.
The query should be modified such that it only returns the latest updated date, and not a collection of all orderables. The query should take no longer than 200ms for a large set of orderables as confirmed by a profiler in the method.
As a part of this ticket, If-Modified-Since support should be restored in POST /orderables/search (after the performance is acceptable).