Reimen is a barrister and nationally accredited mediator. He has a broad generalist practice which includes commercial litigation, administrative law, family law, property law, and human rights. He predominantly focuses on commercial and international disputes.

Before being called to the Bar, Reimen worked as an associate at Wotton + Kearney, a leading international insurance law firm. He has also worked as a lawyer at a boutique Brisbane commercial litigation firm, as a registrar of the Supreme Court of Tonga, at a top-tier national firm, as a judge’s associate, and as a legal officer at a UN-backed war crimes tribunal in Cambodia.

Reimen volunteers with LawRight Inc., the Caxton Legal Centre, and Youth Without Borders. He is a member of the Bar Association of Queensland’s human rights committee; he also a member of the Australian Lawyers for Human Right’s Queensland committee and Business & Human Rights subcommittee. Reimen's dedication to pro bono work and diversity advocacy was recognised nationally by the Law Council of Australia when he was awarded the Australian Young Lawyer of the Year Award in 2019.

Reimen is passionate about diversity and access to justice. Through the AALA he seeks to contribute to the growing dialogue about diversity in the law, and to encourage greater CALD diversity in the senior ranks of the legal profession.