My previous company is slowly opening lines of communication with me again. For context, I left because the new VP of People was destroying our culture...and they were underpaying me to the tune of about $40k as compared to the market average for my role. I joined sub 40 employees, pre-series-B, and by the time I left they were valued at over $1B and crossed the 200 person mark. They haven't rehired for my role and have had it up since I've left (might still be criminally underpaying).
I'm not unhappy with my current role, in fact, it's the scale I like to be at (sub 20 people)...but it's hard not to imagine what you would ask if your previous employer said "name your price/demands" as a means to get you to come back.
What would your last company need to give you to come back, assuming you'd be interested in joining?