|Debut (Anime)||Angel Beats Episode 12|
|Final Appearance||Angel Beats Episode 12|
The unnamed student that Yuri discovered on her quest to defeat the Shadows tells her of a human who became an NPC to await the minisule chance that the girl he fell in love with would reappear in the Afterlife School. He is referred to as The Programmer as he was the one who made the NPC-to-Shadow conversion program and the maker of the AI which Yuri talked to in that episode.
The Programmer's real name is unknown but like Otonashi he was never supposed to have entered the Afterlife but somehow ended up there. He may or may not be the maker of the Angel Player program as it existed before Kanade ended up in the Afterlife. 
During his time in the Afterlife School, he fell in love with an unnamed girl who disappeared when her regret was fulfilled. Unwilling or unable to accept that, he decided to wait for her to return, which from the Afterlife School rules would require her to
- Die during her teenage years (13 to 17 or so for a 4 year gap)
- Have a heavy regret
If the girl lived an average of 85 years and reincarnated each time, there would be a 4/85 (teenage years)*9.83/1000(Japan death rate )*1%(Ad hoc chance of heavy regret)=~0.0004% every reincarnation. Each failure to hit this chance would lead to 85 years of waiting. A 10% chance to see her again would require 2.125 million years. The above calculations do not consider that the majority of the death rate is actually from the elderly rather than from teenagers.
As expected the amount stunned Yuri due to the massive time required to be spent waiting, The AI explained that The Programmer went insane and decided to convert himself into an NPC.
As The Programmer felt that people who had resolved their sadness should not clutter the Afterlife School (much like patients should be discharged when they are cured rather than staying in the hospital), he created a program that kept track of the amount of love in the Afterlife School world. When the amount of love exceeded a certain amount, a "cleaning" program would be acivated where NPCs would be changed into Shadows, which would in turn target humans and forcibly change them into NPCs, thus resetting the world into one where no humans existed.
He still exists as an NPC in the Afterlife but who he is or what he looks like is not known. The AI that Yuri talks to may be based on The Programmer's real look but again no confirmation exists.
The AI that Yuri talks to states that she wouldn't know The Programmer even if he did say his name.