In 1985 Hakim became the organist at Sacré-Coeur, Paris' 1914, hilltop monument to the Catholic faith. In 1993 he moved to the Eglise de la Sainte-Trinité, a seemingly even more prestigious position -- his predecessor there was Olivier Messiaen
. However, Pro-Motion Music quoted Hakim as saying, "The true reason is that Rector Hazemann [at Sacré-Coeur] didn’t want to amend my contract -- my family needed my presence more. I buried my heart at the Basilique du Sacré-Coeur and regret its organ and liturgy as a part of my body and soul." Hakim remained at Sainte-Trinité until 2008.
Since then he has been devoted full-time to composition, writing not only organ music, but also music for other instruments and ensembles, not all of it sacred. Performances and commissions of his music have ranged far beyond France; he has enriched the sparse repertory of concertos for organ and orchestra with the Seattle Concerto (2000). Some of his music, such as the Ouverture Libanaise for orchestra and various organ pieces, has begun to reflect his Arab background. In 2017, the Signum
label issued an album of secular Hakim compositions, including a solo cantata with texts drawn from Racine
's tragedy Phèdre and a recording of the Piano Concerto with Hakim himself at the keyboard.