For modding in general, baseline is checking and handling reports made by users. In addition to that though there can be looking over posts in the instance to make sure none break the rules (sometimes theres stuff like off topic posts made that arent reported)

This community specifically in addition to the above has the solution threads that would require to be posted when the new puzzle drops while AoC runs throughout december

Daily tasks:

• checking reports once a day or something similar and dealing with them
• while AoC is running at midnight ET post a solution megathread and lock it. When the two numbers for the day at https://adventofcode.com/2023/stats get above 100 unlock it (done to prevent cheating on the global leaderboard, only the first 100 scores count there). Usually takes at most 30 mins to reach 100, was much shorter in the early days of the month