@Edent a bit different I know but organising my kids and their friends having a trip to the park never seemed to work out. So my wife had the idea of just making a group with our kids’ friends’ parents and whenever they go to the park we message the group and then get a nice surprise of who turns up.

It’s nice because no-one feels they have to explain why they’re busy or know what they’re doing on some future day. I think your term “engineered serendipity” is perfect.

@Edent I find organized chaos to work best. The organized part is if there's friends I really want to meet I make sure to contact them beforehand to plan around. For the rest, it's mainly posting on Mastodon with a general message, or just enjoy being on my own ;-). (cc @bigcalm, thanks for boosting)

@Edent while you might not be staying at hostels, most of them have a pub/bar, and some of them are nice and social (and everyone is willing/wanting to talk to others)

I don't know if you know of any, but I have also found people on "maps" (map of all "X" maps, like "global map of niche hobby" e.g., freeskating & toki pona speaking)

@Edent I have used Dopllr styled blogposts that only went out through RSS to regular readers. Marked up and all. Like here: https://www.zylstra.org/blog/2025/12/25936/ But hoping to see dopplr redone in activitypub using the proper activitystreams for it.

@Edent I book hostels on hostelworld and use their chat to meet the other people backpacking there at the moment. It always worked but the target age is 18-30 😃

There was this interesting accidental stalkerware called Jabberwocky that worked on that idea that you bump into people every day that you don't interact with, but apparently there's that person in the pub who also buys produce the same time as you every week, maybe you should wave or chat them up.

@Edent I don't know but if you're in Rotterdam I'll buy you a pint*!

*Dutch sizes may vary

@Edent You can announce it as a story on Signal

@Edent dopplr? Sorry, wrong decade.