I'm sure you'll get a fair number of interesting stories here, but you'll find a _ton_ at IndieHackers (https://indiehackers.com) which is a sort of spin-off community from HN that's focuses more on bootstrappers and solo founders.

For me, I launched a five projects in 2021 that were a mix of total flops and sorta-flops, and they all flopped for the same reason:

   * Saascast.io (https://saascast.io/) -- revenue forecasting for Stripe-based SAAS businesses
   * Offramp (https://offramphq.com/) -- Get automatic feedback from unsubscribing customers
   * Donel.ist (https://donel.ist) -- like a TODO list, but more motivating
   * Sandpiper (https://sandpiperhq.com) -- inventory tracking for people who hate inventory tracking
   * Rent Robin (https://sandpiperhq.com) -- automatic rent collection for small businesses

Saascast and Offramp are more or less total flops; I keep them running because I use 'em in all my other projects and I find them useful. They're flops almost entirely because I don't know how to market them, and I'm not convinced that they have enough value-add or PMF to be worth pouring money down the search ads sinkhole.

Donel.ist is, arguably, a total success because it got me out of a moderate depression (being fired and immediately going into lockdown sucks) and back into the habit of building things. It actually has a fair number (50ish) daily users, but it's not monetized at all so in that sense it was a failure at launch!

Sandpiper and Rent Robin are spin-out projects from another, not-failed project -- and while they're not setting the world on fire, they see slow-but-steady growth and the folks who use them seem to love them.

The running theme between all of these is that the projects I build where I already had an audience -- even if that was just myself! -- are successful, and the ones that I built because I had a clever idea but no committed users are failures.