Ask HN: Where should i be looking for co-founders?

Don't look for a cofounder. Just start working. The farther along you get, the more prepared you will be for the "opportunity"... if/when a good potential cofounder comes along. Some people call this luck.

ps. The same advice goes for anyone looking for a romantic partner.

The standard advice is that potential co-founders should come from the people already known well enough that they can be trusted, productive, and committed.

My take is that a cofounder is should be someone I want to make rich and who hopefully wants to make me rich. It shouldn't be an arm's length relationship or the blush of a new love.

Good luck.

Most difficult problem in startups currently imo

Definitely.