I've read the Mom Test, and have realized that I've built too much of my product and tried too many different marketing strategies before fully understanding the market and my potential users.

Where do you guys typically look to find people to conduct user interviews for? I'm currently looking for people here on HN who've complained or talked about something similar to what I'm building (a Medium alternative with a focus on content ownership).

Also, once you find these people, how do you reach out for a call? Don't want to seem spammy or sound like I'm just conducting a survey — generally just want to ask some questions about problems. Especially since with the Mom Test, I want to mention as little about what I'm building as possible.