Why five seats

A bench has five seats. It's an environment variable, so it can be changed in a second, and yet it hasn't moved since day one.

Below that, it stops being a bench. With two people it's a tête-à-tête, and a tête-à-tête with a stranger feels like a date: every sentence carries weight. It takes a third person for silence to become comfortable again.

The ceiling

Above eight, something else breaks. You stop tracking who is who. The names lose their power — Firmin isn't a person any more, he's a label in a list. Messages overlap, replies arrive out of sync, and you get a feed, which is precisely what we were trying not to build.

Five is a conversation you can follow without effort, every name held in your head. It also happens to be how many people fit on a real bench, without anyone sitting on the armrest.

When a bench is full we don't extend it: we create another one. A full bench is still a bench; an elastic bench becomes a room.