Stronghold Engineering, Inc. is a construction and design firm based in California. Originally founded as Stronghold Electric in 1991, the company was incorporated in 2000. Stronghold Engineering, Inc., also known as SEI or Stronghold Engineering, was founded by Beverly and Scott Bailey. Beverly Bailey is the CEO and Scott Bailey is the COO. The main tenets that define the firm are quality, safety, teamwork, integrity, and commitment.

To date, Stronghold Engineering’s civil, infrastructure, and electrical projects have exceeded $2 billion in construction costs. The company provides full-service design and construction support services, including seismic retrofits, tenant improvements, renovations for historical and non-historical facilities, solar arrays, MEP upgrades, battery installations, and underground electrical work. The company also works on civil jobs, including dam work and rail projects.

Stronghold Engineering, Inc. celebrated 30 years of operation in October 2021.