I recently had a bad experience with an interview project with CodeClimate. I put real effort into their assignment and submitted it to them. I wrongly assumed

I recently had a bad experience with an interview project with CodeClimate. I put real effort into their assignment and submitted it to them. I wrongly assumed that as a technical company, they'd have a reasonably respectful process in place for developers. I can accept that my solution somehow might not have been the absolute best implementation the world has ever seen, or they decided not to proceed with me for any reason, but about a month later I got a really impersonal generic rejection message with no indication that anybody even looked at my submission and no response to my very polite and professional followup. The worst though is that some companies are allegedly (cough, Clipboard Health, cough) using job applications for free labor according to Glassdoor reviews.