To add to and explore the last bit of your comment a bit more, medical residency matching is a generalisation of the stable marriage problem — stable means that

To add to and explore the last bit of your comment a bit more, medical residency matching is a generalisation of the stable marriage problem — stable means that between two groups no two pairs can be broken apart where the members of the old pairs can form a new pair which is happier (Only one of the new pairs needs to be happier). If I recall correctly, the algorithm can be biased given that it might need to resolve multiple, competing stable solutions, which is an interesting exercise for whoever is trying to use it (I believe the medical one was changed to favour applicants in recent years). I wonder if there’s a perturbation on the dating app format where the app creates groupings, then invites members to speed-dating style events where rankings can occur (Or just outright pairings if people vibe, but that should be fine because they presumably would be paired later anyway as first choices), and then setup blind second dates with the stable pairs.