Best way to find Technical Writers

Hi HN, I am looking to find technical writers to help with a project that is built on top of an Open Source platform and creates themes/plugins. Think of WordPress but in a more niche area. Where do you find good technical writers to help create great content ? Are there any existing websites that you recommend ?

Also, if you already hire/employ technical writers, would love to hear how you compensate them (per article??), how you set expectations and decide on content etc.