Just a bit of advice: You wrote a sentence about what the service does, and a large paragraph on what it was built on. When you're pitching your service, tell people what's different about your service, why it's better, why they'll want to use it, etc.

I understand that HN tends to be more technical, but the technical details can be a single link. Right now, all I know about your project is that it's a bookmark manager and S3 is better for storing files than the filesystem.

Good luck!