Sergiusz Żemek has over 15 years of experience in general management. He specializes in crisis management, corporate turnaround, and organizational transformation, having successfully led complex restructurings and performance improvement initiatives across multiple industries and countries.

As the creator of the „Harmonic Management” model, Sergiusz has developed an innovative approach that integrates strategic, organizational, and human dimensions to guide companies toward balanced and effective management practices.

Sergiusz is an active member of several international professional associations, including DDIM (Dachgesellschaft Deutsches Interim Management), SIM (Polish Association of Interim Managers), IMWI (Interim Managers with Impact), and AE-CMT (Alumni Association of the Certificate in Interim Management in France).

He now represents Akthéa Polska, a pure player on the interim management market

He also shares his expertise as a management trainer, teaching the „Advanced Management Training Program” in Poland and „Crisis Management” in the Certification Program for Interim Managers in France at IFMT (Institut de Formation au Management de Transition).