MasTec is a large North American infrastructure engineering and construction company. Rather than building end products like power plants or cell towers, MasTec provides the labor and expertise to design, build, and maintain the underlying infrastructure those facilities depend on. MasTec operates across four segments: Clean Energy and Infrastructure (~34% of revenue), Power Delivery (~29%), Communications (~23%), and Pipeline Infrastructure (~14%). Clean Energy builds solar, wind, and storage facilities as well as roads and data center civil work. Power Delivery constructs electric transmission lines, substations, and distribution networks for utilities. Communications builds wireless towers, 5G small cells, and fiber networks for telecom carriers. Pipeline constructs natural gas, water, and carbon capture pipelines. MasTec's customers include large utilities, telecom carriers like AT&T, Verizon, and T-Mobile, renewable energy developers, and data center hyperscalers. MasTec sells primarily through multi-year master service agreements (MSAs), which represented ~44% of FY25 revenue and provide recurring work, and through fixed-price or unit-price contracts for specific large projects. MasTec's profitability is driven by volume and utilization, project mix, and execution on fixed-price contracts. Growth is tied to several long-cycle themes: data center and AI buildout, grid modernization, renewable energy expansion, a natural gas pipeline recovery, and federal infrastructure programs including IIJA broadband and power funding. MasTec argues its differentiation rests on scale, geographic reach, and the ability to serve as a single contractor across multiple infrastructure types for large customers.