A design engineer is a general term for a person who may be involved in any of various engineering disciplines including electrical, mechanical, chemical, textiles, aerospace, nuclear, manufacturing, civil, systems, and structural /building/architectural.

Design engineers tend to work on products and systems that involve the use and adaption of complex scientific and mathematical techniques. The emphasis tends to be on utilizing engineering physics and sciences to develop solutions for society.

In many engineering areas, a distinction is made between the design engineer and the planning engineer in design; analysis is important for planning engineers while synthesis is more paramount for design engineers.

Design engineers may work in a team along with industrial designers to create the drawings necessary for prototyping and production, or in the case of buildings, for construction.

The next responsibility of many design engineers is prototyping. A model of the product is created and reviewed. Prototypes are either functional or non-functional. Functional "alpha" prototypes are used for testing; non-functional prototypes are used for form and fit checking. Virtual prototyping software like Ansys or Comsol may also be used. This stage is where design flaws are found and corrected, and tooling, manufacturing fixtures, and packaging are developed.