From 8 groups of 4 teams, you have 16 teams advancing to the next stage playoffs.
1- A team cannot play against another of the same group from the group-stage.
2- A team cannot face another from the same national league.
What would be the optimal way to model this problem in a functional railway-oriented way.
Something I saw in OO code was one team uber-object with states for each stage of the games and status flags … complicated and just doesn’t look right