Designing for the family, not the individual: how shared rituals create a network effect

Last year my aunt called me at 9pm. “Tomorrow is Grandpa’s death anniversary. Did anyone order the sticky rice?”

Nobody had. Five siblings, three cities, one family chat with 400 unread messages, and the one fact that mattered was buried somewhere in March.

That call is the reason Nhat Nguyet is built around families instead of individuals.

Now the anniversary lives in a family group. My aunt added it once, on the lunar date, and it reaches all of us every year. Two weeks before, a plan appears: sticky rice, fruit, flowers, who drives Grandma. Each task has a name next to it. When my cousin ticks “fruit”, the rest of us see it. When someone asks “three trays or five?”, the answer sits under that exact date, not in a chat that scrolls away.

Afterwards we add photos, and they’re grouped by year. Scrolling back through four anniversaries is strangely moving: the kids get taller, Grandma sits in the same chair.

I never set out to build a “network effect”. But every relative who joins brings their own dates and their own people, so the calendar fills itself. A cousin’s wedding anniversary shows up, then an uncle’s mother-in-law’s memorial day. The app gets more useful the more of the family is in it, and lunar dates come back every single year.

One rule we kept: no streaks, no guilt pushes, no promotions unless you opt in. Families already have enough people nagging them.