Willdan Group, Inc., together with its subsidiaries, provides professional, technical, and consulting services primarily in the United States. The company operates in two segments, Energy, and Engineering and Consulting. The Energy segment offers comprehensive audit and surveys, program design and implementation, master planning, demand reduction, grid optimization, benchmarking analyses, design engineering, construction management, performance contracting, installation, alternative financing, measurement and verification services, and software and data analytics, as well as energy consulting and engineering, turnkey facility and infrastructure projects, and customer support services. The Engineering and Consulting segment provides building and safety, city engineering and code enforcement, development plan review and inspection, disaster recovery, geotechnical and earthquake engineering, planning and surveying, contract staff support, program and construction management, structural engineering, transportation and traffic engineering, and water resources services.