Mr. Halder is working as an environmental expert of a number of Environmental Assessment and Environmental Monitoring studies of industrial and infrastructure development projects funded by national and international financial agencies and banks. He plays versatile role in those projects like environmental modeler, ecologist, environmental auditor, occupational health and safety specialist, environmental management specialist, environmental economist and technical specialist etc. Academic skill, national and international training and multidimensional working skill have made him confident to guide the study team effectively and efficiently. Additionally, he performs as a trained SEA expert. He performs as a trainer on the subject of environmental modeling, health and safety, EIA study and natural resources management.