Kind of close with TokenSets[0] managing Mirror[1] backed assets.

Things like the DeFi Pulse Index[2][3] I believe are automatically re-balanced by evaluating the weights on the third week of the month and then applied the first business day of the following month. I'm not sure if a human is involved?

[0] https://www.tokensets.com/portfolio/dpi

[1] https://mirror.finance/

[2] https://www.tokensets.com/portfolio/dpi

[3] https://www.pulse.inc/