Blood sacrifices and invocations to see who can summon the cutest and fiercest beast. You show your demon to the camera and get votes on it and on the chants you did to bring it from the depths. At the end of each sprint.

Remote orgies to appease the gods of nature and ensure a good deployment. Everyone wears traditional handmade masks for anonymity and we only do it if all tests are green, obviously. Every three months or so; depends a bit on the moon.

Previously we tried more traditional stuff like fire walking but we had to stop doing that one because a guy in another team wasn't careful setting up the coal, ended up burning the company laptop, and then HR banned it ¯\_(ツ)_/¯

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Edit (for constructive commenting):

I guess I don't like rituals. I much rather prefer a less forced environment for more spontaneous and relaxed communication.

That's not to say you can't have some habits or whatever, but I feel most of those "cool ideas" always end up feeling tiresome to some part of the group if they don't grow from the people themselves.