Sales engineers have to be good enough to bluff their way through the layers of hyperbole/minor exaggeration/utter bullshit (delete as applicable) the sales team have spun. Whether their conscience gets involved before the deal closes, different question.

"Webdev" makes me think of wordpress, which is like planting 20 onions in your backyard, and comparing yourself to a farmer with acres of crops.

I can completely believe someone had no idea what they were doing when copy/pasting, and working on wordpress.

Yeah, and the business people could not care less. I am on a team taking in millions of dollars from a Delphi Windows app from 1997. Zero tests, horribly mangled business logic embedded in UI handlers. Maintaining that app is not feasible. I'm rebuilding a modern version of it only because it is embarrassing to demo and is such a UX nightmare that our distributor made us commit to a new app.