Alex Melaku was one of four gang members who stabbed the "entirely unsuspecting" victim to death on a London street last year.
Melaku, of Bishopdale, Brookside, could not previously be named due to being aged under 18 but was identified on Friday as the four murderers were sentenced.
Mr Gomoh was repeatedly stabbed on April 26 last year as he spoke to his girlfriend on the phone, having been in the "wrong place at the wrong time".
The 24-year-old marketing graduate, who worked in procurement for the health service, staggered back to his home in east London and bled to death in front of his horrified family.
In victim impact statements read at the Old Bailey by prosecutor Peter Ratliff on Friday on behalf of Mr Gomoh's mother and sister, the horror of his death and the subsequent trauma inflicted on his loved ones was laid bare.
The court previously heard how Mr Gomoh was stabbed in Freemasons Road, Canning Town, as part of a "meaningless feud" that sparked a "petty but fatal game of one-upmanship" played out on the streets of London.
During the trial, jurors heard the victim had nothing to do with gangs.
Alex Melaku was found guilty of murder alongside three other men in August.
David Ture, 19, of no fixed address; Vagnei Colubali, 23, of Cambridge, and Muhammad Jalloh, 19, of no fixed address, were also convicted.
All four were handed life sentences with Melaku, who turned 18 the day before the sentencing hearing, locked up for life with a minimum term of 21 years.
Colubali and Jalloh given minimum terms of 27 years while Ture was handed a minimum of 26 years.
Judge Mark Lucraft QC, the Recorder of London, said the killers had carried out a "brutal murder" which had involved a "significant degree" of planning.
He said: "The four of you are part of a north-side Newham gang, who have a feud with gangs on the south-side of the borough.
"I have no doubt there are many who live in all parts of the borough impacted by the acts of those like the four of you, who seem to kill simply for the sake of it and show little or no regard for human life."
He added: "David was a lone, innocent and entirely unsuspecting victim."
Mr Gomoh was in the "wrong place at the wrong time", he said, adding that he was stabbed no fewer than 10 times during the incident in Freemasons Road, with some of the wounds being almost 20cm deep.
Mr Gomoh's family were already in mourning at the time of his death, as his father had only recently died.
In a victim impact statement, his mother Marian, said she is "haunted" by recurring nightmares about what happened, adding: "I felt numb, paralysed by grief and pain. Why David?"
She said the "psychological and emotional torture escalated" during the trial, as she listened to details of what happened to her "beautiful son".
She added that he had "so much to live for; so much unfulfilled promise and so much needed by the NHS trust he worked for to help distribute PPE and other stocks, so much humanity and compassion to share".
She said her son's murderers had "walked uninvited into our lives and destroyed David's life".
The defendants have "wrecked our family", she said, adding: "Their contempt for a human life is just beyond comprehension."
His sister Lizzie paid tribute to her "fun-loving, amazing brother" and said his death has had a "devastating impact on us all".
She said: "It still feels so raw and so fresh."
Referring to her brother's killers, she said: "I hope they will eventually show remorse."