Koomson was born in
Accra, Ghana. He played for
BEC Tero Sasana in the Thai FA Youth Cup and also being call to
Ghana national under-17 team. Previously, he spent time in the Ajax Accra F.C. in Ghana.
Stoke City called him to go on trial but he had a problem with a visa and thus was unable to earn a work permit. He came to Thailand to improve his career of professional footballer under the guidance and recommendation from BEC Tero Sasana Technical Director
Peter Butler, (Ex
West Ham United) who was coaching Koomson while he was guest coaching at the
Manchester City academy in Accra Ghana. Koomson went to European football when signing for
Sogndal in Norway. After two seasons at Sogndal, Koomson signed for
Brann ahead of the 2018 season. ==International career==