You don't. When your server crashes, your availability is zero. It might crash because of a myriad of reasons; at some times, you might need to update the kernel to patch a security issue for example, and are forced to take your app down yourself.
If your business can afford irregular downtime, by all means, go for it. Otherwise, you'll need to take precautions, and that will invariably make the system more complex than that.
If your business can afford irregular downtime, by all means, go for it. Otherwise, you'll need to take precautions, and that will invariably make the system more complex than that.