Nelson "Big Head" Bighetti was a tenant of Erlich's incubator and is Richard's friend. He is hired by Hooli on a huge promotion to work on Nucleus, Hooli's version of Pied Pier, and to spite Richard. After Big Head is removed from the Nucleus project due to his limited tech knowledge he begins to rest and vest. Later he is promoted to Sole Head Dreamer at Hooli XYZ, a bullshit title and department, because Gavin wants to sue Pied Piper by arguing that Big Head came up with Pied Piper's algorithm while at Hooli.
https://www.youtube.com/watch?v=7bPAiAE7COo
https://www.youtube.com/watch?v=zFhrjtZBV_k
https://www.youtube.com/watch?v=Vwo5rjlLhTo
https://www.youtube.com/watch?v=fM67VYO8qeo