Assystem S.A. is a global provider specializing in engineering solutions and infrastructure project management. It offers comprehensive engineering support for the planning, conceptualization, and execution of intricate and vital infrastructure initiatives, primarily for government bodies and public utility providers. Beyond its core engineering focus, the company delivers a comprehensive range of additional services. These encompass engineering, procurement, and construction (EPC) management; project management consulting; industrial control system solutions; site location and permitting studies; research and analytical services; systems engineering; general project management; digital engineering; project control solutions; digital field services; and industrial data science. Assystem also provides crucial compliance, safety, and security services across key sectors such as nuclear, energy, transportation, defense, and broader building and infrastructure projects. Its portfolio further extends to decommissioning and waste management, as well as integration and ongoing maintenance services. Established in 1966, with its headquarters in Courbevoie, France, the firm was known as AssystemBrime S.A. until its rebranding to Assystem S.A. in June 2005. Assystem S.A. operates as a subsidiary of HDL Development.