No matter how much you prepare, you will never be ready for everything. Most of things you learn arise from real problems you encounter on the job. So don't try

No matter how much you prepare, you will never be ready for everything. Most of things you learn arise from real problems you encounter on the job. So don't try to figure out if you're prepared. Analyze it from an opportunity perspective. Opportunity is knocking. Are you going to answer or are you going to ignore it? My advice is to jump on every opportunity. Because they never come in groups. With that aside, sounds like the CEO wants you to build his app for free. I may be wrong. But the wording is pretty standard. "Common vision" and "any developer can do it, but I like you" are usually red flags. You want to hear things like "Here is what we want to do, what are your thoughts about it?". You want to be involved. Not a disposable code monkey taking orders and instructions.