Solo Founders: What's the one thing that keeps you up at night?

I'm currently 4 days out from my first big launch, and I've spent the morning triple-checking everything.

As an individual contributor, I find that silent failures are the biggest stressor - the things that break without an alert or a ping.

For those of you building alone, what's the one part of your stack or business that gives you the most anxiety?

• Is it the billing logic/edge cases?

• Is it the server scalability?

• Or is it just finding the time to do marketing while shipping code?

I'd love to hear how you all manage the fear of the unknown when you don't have a team to check your work.