While we're on the subject: can anyone recommend a good resource on how transaction processing systems work, at as low a level and high detail as possible?
http://engineering.gusto.com/how-ach-works-a-developer-persp...
http://engineering.gusto.com/how-ach-works-a-developer-persp...
http://engineering.gusto.com/how-ach-works-a-developer-persp...