An opportunity just opened up in my dream company, but my experience doesn't measure up. What do I do about this?
You don't know when that dream job's going to open up for you. You don't know when a big client will notice your business and see what you have to offer. But what you do know right now, is your current value and the value of someone in the place you aspire to be.
Gradually bridge that gap by constantly preparing yourself. Do one small thing everyday that will increase your value, making you better prepared for when life randomly throws you that opportunity to make your big break.
The product you make doesn't have to be great at first. It can be bad. Actually, it will be bad, but do it anyway. Identify what improvements could be done, then iterate the next day. Even if you work on it for just 30 minutes everyday. Do this for a year and you will notice a huge difference. Consistency, and persistence is key.
Now go out there and hack your luck.