Under Hartati's leadership, Walubi is involved in post-disaster relief work, as well as missions where medical staff of different faiths volunteer to provide free treatment, such as cataract removals, cleft-palate corrections in children, tumor removals and dental care, to thousands of patients. Hartati organizes and participates in many of these missions herself. After the 2018 Sunda Strait tsunami, which killed over 400 people and left over 14,000 homeless, Hartati was involved in the provision of relief aid.