I did some terrible things when I was 19 that I won't go into details, but after working as a developer for a few years, served a six-year sentence from 2003-2009.
Upon release, I leveraged some old contacts to get a bit of contracting work. In time I found more contracting work, mostly working for smaller companies on a 1099 basis. (direct, not through a firm) In time a local contract turned into a job, and I've been with the company since. I'm the lead developer and own the entire stack, from the cloud to the front-end. I've made myself very valuable to them, and earn an income that's well over market (early on they offered me a percentage of profits as compensation)
I still continue to do contracting on a small basis (small companies tend to not bind you with onerous terms keeping you from doing so). Some of them I've even found on HN.
Anything involving a background check is a no-go. Most traditional employment situations, especially with "big" companies is a no-go. Sometimes you have to hustle a bit more, but honestly, I feel like owning your career with an entrepreneurial mindset is something everyone can benefit from.
Most of my clients have no idea about my past. A few have learned, but it didn't disqualify me. I was transparent when asked.
You should know that if you also have a non-throwaway account, HN will unify your accounts in their backend records.
Yes, you should assume that the moderators will know, and you should be fine with them knowing, because you’re not using the multiple accounts to escape moderation, but rather for greater anonymity in the comment thread.
The rules that I follow, which I think are implicit in “use good judgment”:
1. Don’t vote on the same thing from multiple accounts.
2. Don’t participate in the same comment thread with multiple accounts (or if you do, only separate parts of the thread). Don’t create a fake impression of consensus or have your accounts interact with each other.
Those are probably the two big ones I would imagine.
Whether the accounts are actually tied together on the backend, I don’t know. I would suspect that they are not automatically linked, but could probably be linked if the moderators are investigating you for bad behavior (like voting on the same thing with multiple accounts).