I've worked in Architecure, Civil Engineering, and Mechanical Engineering for the past 15+ years. I'm currently an architectural designer but do product design as well as furniture/interior design as a hobby.
Architecture (software - AutoCAD, Revit, and Chief Architect): I've design residential houses using CMU block (Florida) and also using conc. poured basement foundations with framed walls (BC, Canada). I have also design houses with ICF construction and know current architectural standards and building codes. A lot of the current styles I design are modern, craftsman, and Mediterranean style houses.
Mechanical Engineering (software - solidworks): I've worked several years in the mechanical design field and have worked with gears, flanges, piping, plenums, sheet metal, CNC programming, and welding/bending/tolerances.
Product Design (software - solidworks): I've done some work with product design, have read and researched ways products are manufactured, and have designed improvements on current product trends. Plastic molds are a dominant feature for product design and knowing your type of plastic and its use play major roles during the design process.