What part of building and shipping software takes longer than it should?

I've been thinking about how much of software development happens outside the actual product.

You can spend time setting up authentication, connecting databases, managing infrastructure, configuring integrations, and handling deployment before you get to the features that make your application different.

I built Mudbase BaaS around some of these backend problems, and we're also exploring how AI-assisted development and code execution can simplify different parts of the process.

I'm curious about the experience of other builders here.

What's the most frustrating part of taking an idea from a prototype to a working application?

Is it the backend setup, infrastructure, integrations, deployment, or something else entirely?