Matan Assayag was born in Jerusalem in 1987 and started on drums at age 7. By 11 he was already playing and recording professionally alongside established Israeli artists. He graduated Jerusalem Art School in 2005 and continued studying with private teachers, then, after completing his military service, joined the honors jazz program at Tel Aviv's Stricker Conservatory at age 23, run in partnership with the New School in New York.

His best-known work traces back to a teenage friendship. He and pianist Gadi Stern grew up playing together in Jerusalem, in a band called Enoma Elish that released the album Taking Bobby for a Walk in 2007. When that group ended, the two kept working together, and in early 2014 they formed the piano trio Shalosh in Tel Aviv, with bassist David Michaeli joining in 2016 to complete the lineup. Shalosh has since recorded for ACT Music and Neuklang, played full-orchestra dates with the Würzburg and Trier Philharmonics, and sold out Hamburg's Elbphilharmonie; the band is profiled separately on jazzprofiles.com.

Alongside Shalosh, Assayag is a founding member of the Hoodna Afrobeat Orchestra, a 12-to-14-piece Tel Aviv collective formed in 2012 that operates as both a touring band and its own record label. It is a different musical world from Shalosh's piano-trio jazz-rock, built on Afrobeat rhythm sections and a full horn section. In 2023 the orchestra invited Ethio-jazz pioneer Mulatu Astatke to Tel Aviv to record together; the resulting album, Tension, was released November 8, 2024, with Assayag driving the beat under the group's brass on the title track.

He also runs his own recording studio, Hoodna Studio, and privately teaches more than 25 students.

Assayag's playing spans two distinct idioms rather than one signature style: the melodic, genre-crossing jazz-rock of Shalosh, where the trio reworks pop and rock songs (Nirvana, a-ha, Oasis, Aqua) into instrumental jazz vocabulary, and the polyrhythmic, horn-driven Afrobeat and Ethio-jazz of the Hoodna Orchestra, most directly shaped by exposure to Ethiopian, Eritrean, and Arabic musical traditions. The throughline across both is a drummer comfortable inside repertoire far outside a standard jazz songbook.