I noticed in your blog that you're using Amazon EC2. Why did you make this choice? The company's compute needs, presumably fast compilation and lots of I/O with

I noticed in your blog that you're using Amazon EC2. Why did you make this choice? The company's compute needs, presumably fast compilation and lots of I/O with relatively few spikes, seem exactly opposite of the tradeoffs EC2 is engineered to do well (handling highly variable compute loads without major I/O or compute needs)