[1] Born in Conakry, Guinea, Soumah began his football career playing on the streets,[2] before moving to South Africa and joining the youth system of Ajax Cape Town as a teenager.

He was initially sent out on season-long loans to National First Division sides Ikapa Sporting (2008–09[3][4]) and FC Cape Town (2009–10), before returning to his parent club.

[5] On 21 January 2011, Soumah made his debut for Ajax in the Premier Soccer League, coming off the bench in a 3–0 away victory against Platinum Stars.

[10] On 14 September 2012, Soumah received a red card in a 3–1 home league loss to Spartak Trnava, alongside two other teammates.

[11][12] He was later fined €3,400 and banned from football for six months for making an obscene gesture towards fans, assaulting the opponent's players and threatening the referee during that match.

In July 2014, Soumah celebrated by lifting the Slovak Super Cup trophy after Slovan beat MFK Košice 1–0.

Two days later, Soumah made his debut for Partizan as a second-half substitute in an eventual 6–1 home league victory over Mačva Šabac.

[26] On 2 August, Soumah scored a goal in a 2–2 away draw with Olympiacos in the return leg of the UEFA Champions League third qualifying round, as Partizan got eliminated 5–3 on aggregate.

[27] He later scored in a 4–0 away win over Videoton in the second leg of the UEFA Europa League play-off round, helping the team progress to the group stage.