Got a "Thanks, you're not moving on" message and that was it. Man, the rejection is totally fine, but I really do wish they could've spent a few min just explaining some details. I've gotten more thoughtful rejections from just cover letters and resumes, not to mention public PRs in strangers' repos.
After spending so much time, it just feels like a betrayal of some unspoken developer ethos (vs say talking to a generic HR screener). If you're going to make someone code for you for hours and then dismiss their work, please at least tell them why in just a few sentences. You don't need to comment line by line in a code review, just general thoughts like "better code org" or "poor architecture and readability" or "better tests would've caught this major bug" or whatever.
In my case this was a small company I was super excited to work for, and waited more than a year to finally have a chance to apply for (once my current job ended). It was definitely disheartening and makes it hard to want to try again with them in the future.
But, you know, the other side of the coin is that maybe they're just getting swamped with so many applications they can't take the time to thoughtfully answer each one. I imagine I'm competing against a horde of more qualified ex FAANGers right now and maybe they're too busy trying to decide between the top 3 or 4 vs the long tail of hundreds of us who failed the take home. Who knows...