Moderators enforce quality thresholds and keep trolls out that makes those communities possible.
They used lots of custom bots to do this. Many, such as bots that detected abuse from users, used Pushshift, an API and front-end for crawling through archived Reddit posts. (Reddit's API limits you to 1000 posts/thread and has rate limits on the number of posts you can search through.)
Apollo and other apps aside, a large chunk of the protests from moderators were because of how the API would render their moderation bots completely useless and Reddit's inability to provide better alternatives.
Most vocal amongst them was the moderation team of /r/AskHistorians, an extremely well-curated sub that heavily used bots to enforce their very high submission and participation standards.
They used lots of custom bots to do this. Many, such as bots that detected abuse from users, used Pushshift, an API and front-end for crawling through archived Reddit posts. (Reddit's API limits you to 1000 posts/thread and has rate limits on the number of posts you can search through.)
Apollo and other apps aside, a large chunk of the protests from moderators were because of how the API would render their moderation bots completely useless and Reddit's inability to provide better alternatives.
Most vocal amongst them was the moderation team of /r/AskHistorians, an extremely well-curated sub that heavily used bots to enforce their very high submission and participation standards.