During the period of approximately seventeen years, Mau has worked exclusively in the field of Land Administration specialising in an integrated land information system, first as a GIS/LIS researcher, research fellow, and later as an LIS analyst. His experiences include development of software and related decision-making support systems for Vietnam Land Information System (known as ViLIS) and assisting the government agencies to implement and manage that system. Later, he worked for General Department of Land Administration (GDLA). At GDLA, Mau is one of the key officials assigned to develop a development strategy for National Land Information System (NLIS), clarify conflicting regulations and streamline them; built a methodology for data-sharing and updating between various government agencies and drafting of legal texts and guidelines, administrative circulars on cadastral data content standards and land registration services standards.