Ask HN: Feedback from hackers on unpublished articles

I've recently begun writing again, and I'd like some way to get critique of my writing before it's published. Ideally, it would be something I could use in the future, as well.

I don't know any hackers personally (the tech scene in Alaska is pretty sparse), so I can't turn to personal connections.

To clarify - I don't need proofreading, I need critique. I'd like feedback on my structure, sentiment, and argument, not on my grammar and spelling (if issues with grammar and spelling were found, that would be fine, but I don't tend to have much of a problem with that.)

This could be a startup idea, if it's not already implemented, but I would like something that already exists, if possible.