Ask HN: Community or resources for eliciting product or company feedback

Earlier this month I participated in the Small Product Lab by Gumroad which challenged participants to take a product from inception to delivery in 10 days. It was an awesome and exhausting experience and the best part that I got out of it was a private Facebook group where you could seek feedback, poll others in similar places as you and overall just ask questions. HackerNews is great for asking questions once and a while (especially when the questions are common to many people) but it's obviously not the best medium should one person have, say, 2 or 3 questions this week and another question a week later. So what I'm wondering here is: is there a place (or places) where people who want to make products, are part of a start-up, etc where they can look for feedback on various things about their product and / or company? I think a forum may be a good format for these types of things but I haven't found any that seem to fit the bill.