For a house or any habitable structure on North Texas clay: yes. Cities require an engineered foundation plan to permit one, lenders expect it, and Texas licenses the engineers who produce them through TBPELS. Metal buildings build to the manufacturer's engineered drawings. A simple equipment pad usually does not need one.
More detail
The engineering question sorts cleanly by what the slab must do. Habitable structures (houses, barndominium living space, commercial buildings) get engineered foundations here, full stop: the expansive Blackland clays move enough seasonally that corridor cities from McKinney to Sherman require a foundation plan sealed by a Texas-licensed engineer before they issue a permit, and lenders and insurers expect the same paper. The engineer works from the soil (sometimes a geotechnical report, always the regional knowledge) and designs the answer: commonly a post-tensioned slab or a conventionally reinforced slab with deepened grade beams, tuned to the lot. Pre-engineered metal buildings sit in the middle: the building manufacturer supplies engineered reactions and anchor layouts, and the slab is designed to receive them, with a local engineer involved where the city or the project size calls for it. Simple flatwork (a patio, a parking pad, a driveway) does not need a stamped plan, and paying for engineering it does not need is as much a miss as skipping engineering it does. Two things the engineer's involvement buys beyond the permit: an independent check on any contractor's proposal, since the design is not produced by the person selling the concrete, and resale documentation, because "the foundation was engineered for this soil, here is the sealed plan" is an answer buyers and inspectors accept.