Jack Shedd on why should be no separation between design and engineering:

The idea of design divorced from engineering is laudable, but the way it so often plays out makes it implausible. Yes, in theory, the design team should come up with a perfect solution and the engineering team should be smart enough to figure out how to pull it off and neither should ever have to talk to each other. The resulting product would look exactly as designed and would work perfectly. Keep on trucking you radical dreamer. Here’s a quarter for the jukebox.

The world’s supply of brilliant-the-first-time designers and can-figure-anything-out engineers is not nearly vast enough. While the ranks of folks who think they’re the former is exponentially higher than the folks who think they’re the latter. As an industry where the two sides are so co-dependent on each other, that either group would think of the other’s role as trivial is beyond ridiculous.

This separation can be particularly tragic when the “get client approval” step falls between design and engineering.

In the most absurd case, I’ve worked on projects where one person acts as both designer and engineer, designs without the engineering in mind, and comes to regret the box they’ve put themselves in.