Prior to joining ICHESS, he worked as a data and statistics specialist at the National Sickle Cell Program (PNLCD) at the DRC Ministry of Health and was also Deputy National Coordinator of Enhanced Monitoring for Action (MAA), principal investigator and co-investigator of clinical and population surveys.

As an expert in strategic and operational planning, he supported several central directorates and specialized programs of the DRC in the drafting of their strategic plans.

Her area of expertise includes health systems strengthening,  monitoring, evaluation, accountability and learning (MEAL), prevention and management of the 3 killer diseases of the child, reproductive health and family planning, HIV and tuberculosis, WASH, functional rehabilitation  and strategic and operational planning.

As a MEAL expert, he participated in nutritional research including the evaluation of the determinants of visceral and subcutaneous adiposity and cardiovascular risk factors in several population groups in the city of Kinshasa; assessing the growth of school-age children in the city of Kinshasa;

within the framework of the MAA, the monitoring of clinical, community and advanced strategy interventions including the integrated management of acute malnutrition (PCIMA),

exclusive breastfeeding (AME) and complementary feeding with more than 10 Provincial Health Directorates (DPS) and more than 50 Health Zones (ZS) to its credit. Gullit was also a member of the National steering committee on RMNCAH-Nutrition.

Gullit has supported several DPS and ZS of the DRC in MAA sessions and in the implementation of the monitoring and evaluation of programs/projects such as the capacity building program in perinatal care, the ZS evaluations in the context of the introduction of the CFC-RTM, the state of progress of FP in the ZS PATHFINDER, the evaluation of the reco (Community Relay) support program of HPP-CONGO,

the CARAMAL project, the clinical mentoring program to improve the quality of emergency obstetric and neonatal care, the community observatory for the management of PHA, the monitoring of the Mother-Newborn Couple project,the monitoring of the women’s groups project (ASC-women)

and the evaluations of the Signature program of SAVE THE CHILDREN. It has also supported various operational research projects such as the assessment of the impact of COVID-19 on RMNCAH-Nutrition in the city of Kinshasa and the state of pneumonia in the DRC in children under 5 years of age.