Apothecary Diaries - The medical professionals if they had group chats (this takes place in the canon universe and time period but phones inexplicably exist just for groupchats and nobody questions it):
Work Group Chat - Hosted on a platform similar to Slack. Has all of the medical professionals, including Dr. Liu and Luomen. Almost entirely serious and work-oriented, but you just know that Guen (the Quack Doctor) posts "GOOD MORNING DON'T FORGET TO SMILE!!! 😁😁😁☀️" type gifs and cat gifs all the time and nobody has the heart to tell him to stop. Dr. Wan-wan and Yo think it's kinda cute though. The bosses originally planned not to tell Guen about the work chat but one of the younger workers accidentally let it slip, so now he's there. Sometimes, Guen comes crying asking for help on very basic things and Luomen has to gently walk him through it. Meanwhile, everyone is passive aggressive to Tianyu when he speaks in this chat. Also, En'en agrees with/gives 👍 emoji reacts to Yao when she says literally anything.
The No-Tianyu-Allowed Group Chat - Hosted on a different platform. Has all of the younger people in it (Maomao, Yao, En'en, Dr. Wan-wan, Dr. Li, Yo, Changsha, and others) minus Tianyu because they all agree he's annoying as hell. At first, it's mostly just used for things they don't want to say around Dr. Liu. But then it evolves into just hating on Tianyu—especially after what he did during the Emperor's surgery and his punishment ("the lashings 😭😭😭" but, like, literally)—and seeing whose turn it is to torment him this time.
Maomao, Yo, and Changsha - Offshoot with just these three. Changsha uses this one solely to vent about how immature Yao and En'en are. Yo spoke when it was first created but has since been totally inactive in this chat despite talking to Changsha a lot elsewhere. It's basically just Changsha ranting to Maomao who tries to be levelheaded about it. Basically a Maomao & Changsha DM in all but name.
Active DMs
Yao & En'en - En'en always checks in on her mistress when they're separated for any significant (i.e. >6 hours) amount of time
Yao & Changsha - After the LN16 dinner, Yao is like, "Please teach me, Changsha 🙏🙏🙏" and she lets Changsha be merciless to her in this chat as a form of therapy (it's also pretty cathartic for Changsha, too). Yao is careful not to let En'en know but En'en is very suspicious of how she's been acting lately
Maomao & Dr. Wan-wan - One day, Dr. Wan-wan DM'd Maomao a fun fact about body parts and she was like "Whoa that's so cool tell me more" and then it just became a thing where he regularly messages her fun facts and Maomao earnestly goes "Omg that's awesome" every time. Both Maomao and Dr. Wan-wan subconsciously believe it's a platonic thing, similar to Maomao's time with Lihaku, but let's pray Jinshi doesn't find out about this chat
P.S. I would say we need more Dr. Wan-wan appreciation, but really we just need more appreciation for AD's medical professionals in general