Google or-tools are quite fun although a little bit of a pain to setup and get started at least if you want to use the JVM and support different OS.
Just to share a little anecdote about my use case: The department I work in consists of about 40 developers and once a year we had a day together just to form new teams in a self organized manner. Management wanted about one third of a team to move to a different team to spread and gather knowledge but completely backed off during that day.
We had a special coach and scrum masters supporting us but still it was very exhausting and a lot of the developers didn't like it. The devs that showed motivation to change teams were more or less forced to go to the teams which were disliked the most (either because of their domain or the already present members).
So in the end there was not much rotation and the whole thing was quite expensive so that this year it was cancelled. That's when I started to use Google or-Tools to write a little tool that suggests teams based on some constraints like size, at least one experienced dev / software architect per team and an optimization function based on preferences of each dev for a certain domain as well as their sympathy towards other devs
When I announced it it got almost no attention and was dismissed as "inhuman".
