The API allows you to grab the history as of a date, so that would limit the amount of data in the json - maybe limit it to a date since the last check. (see DirkZ response to this post from a couple of months ago: https://matillioncommunity.discourse.group/t/in-matillion-we-have-a-task-history-which-is-really-having-detailed-data-is-there-any-way-i-can-use-those-data-and-trigger-an-email-like-failure-jobs-task-history-or-some-specific-job-task-history-curious-to-know-any-suggestions-please/1372)