Jaroslav Lexa has been involved in public procurement since the mid-1990s. He uses his practical experience from carrying out various purchasing processes (through VO rules) in teaching and educational activities. He promotes the application of innovative procedures in this area, including responsible procurement, especially the social aspect and environmental protection.

From 2018 to 2020, he worked as the director of the Institute of Public Procurement at the Office for Public Procurement, where he mainly deals with analytical work, building a pro-client approach and education in the field of public procurement. After being appointed as the vice-chairman of the Office for Public Procurement, he acts as a member of the Council of the ÚVO (second-level appeal body) and is also entrusted with the management of the Institute of Public Procurement.