If you're thinking "If I can get a job at XYZ start-up I must be a brilliant coder", so it's essentially a validation of your ego, it's probably not brilliant.

If you look at it as a challenge where you'll be working on something new, where what you write makes a very visible difference to the product, in a fast moving environment, where you'll meet people who don't mind taking a risk (usually more interesting folk than the cautious ones who work in corporations) ... it's completely awesome.