In every recruitment details, you can find a "TODO" tab.
Those are the reminders, telling you what needs to be done with the candidates in this particular recruitment.
Every TODO has a:
STATUS - is it upcoming one, or was it already done?
STAGE - in which stage of the recruitment it was added
CONTENT - what exactly should you do with that candidate?
CANDIDATE - which candidate it is about
DATE - when it should be done
OWNER - which user (recruiter) added it.
You can filter the TODO's by Status, Stage, Date and Owner field.