It's quite good. Since you have been in grad school already, many of the things won't be news to you.
I would say that the fact that you left grad school for a Wall Street job will hurt your application. The admissions committee might think that you're not determined and self-motivated enough for grad school. They might think "If this dude likes CS so much, why didn't he jump to the CS department back then?". Might be a good idea to explain in your statement of purpose that you discovered your passion for CS while in Wall Street.
"Applying to Ph.D. Programs in Computer Science", by Mor Harchol-Balter ( http://www.cs.cmu.edu/~harchol/gradschooltalk.pdf )
It's quite good. Since you have been in grad school already, many of the things won't be news to you.
I would say that the fact that you left grad school for a Wall Street job will hurt your application. The admissions committee might think that you're not determined and self-motivated enough for grad school. They might think "If this dude likes CS so much, why didn't he jump to the CS department back then?". Might be a good idea to explain in your statement of purpose that you discovered your passion for CS while in Wall Street.