One puzzle for the whole planet, generated from the date. Here is why that single design choice carries the whole product.
There is no technical reason a puzzle site has to give everyone the same board. It is harder to build that way. We do it because it is the only decision on this site that actually matters.
A shared board is a conversation
If I tell you I scored 2,410 today, that number only means something if you also played today. Shared puzzles turn a private activity into a social object: you can compare, you can gloat, you can complain about a nasty board together.
Deterministic generation makes it free
Every board is generated by an algorithm seeded with the UTC date, the game and the level. Nobody writes puzzles, nobody edits them, and nobody has to. The marginal cost of a new day is zero, which is what lets us promise a new puzzle every single day without a content team.
It makes the leaderboard honest
When everyone plays the same board, differences in score come from the player, not from the luck of the draw. That is what makes a percentile worth looking at — and it is why the ability profile means anything at all.