Rabea Joachim was born in the Ruhr area. In addition to an early education in the subjects violin and piano, she received her first composition lessons at the age of thirteen with Prof. István Nagy. Composition lessons with Prof. Martin Christoph Redel followed as part of her young studies at the Detmold University of Music. Rabea Joachim completed her Bachelor in Composition at the Folkwang University of the Arts Essen until 2019 with Prof. Günter Steinke and Prof. Dietrich Hahne. She received further important impulses from Prof. Moritz Eggert and Prof. Peter Michael Hamel.
In addition to first prizes and a federal prize in the Jugend komponiert competition, she won the Berlin Philharmonic's Opus One competition in 2015. In this context, the Sharoun Ensemble performed the world premiere of the prize-winning octet in the Berlin Philharmonie. On the occasion of the 30th anniversary of the unerhörte Musik series, the Berlin Modern Art Ensemble performed her piano sextet for the first time. Further premieres of ensemble and orchestral works were given at the Semanas Musicales festival in Frutillar, Chile, the Space City New Music Festival in Houston, USA, and the Weimar Spring Days for New Music, among others.
Rabea Joachim wrote her first stage works for the Neuköllner Opera in Berlin, while her modern sequel to the children's opera Brundibár was written for the Opera Factory at the Theater Freiburg.