Whenever I pick up a part, any part, I can tell a lot about the engineer who designed it.
Most people see “a piece of plastic.”
A product design engineer sees decisions, tradeoffs, constraints… and sometimes compromises.
Here are the 5 things I look for immediately and what they reveal:
Gate location
Tells me whether the designer understood flow, knit lines, surface requirements, and where they were willing to hide imperfections.
Draft
You’d be surprised how many parts still make it to tooling without proper draft.
If it’s missing or inconsistent, it usually means the design was rushed, or someone skipped a DFM review.
Ejector pin marks
Clean layout = intention.
Random, scattered, or visible on an A-surface?
That usually signals late changes or weak collaboration with tooling.
Ribs & bosses
Good ribs tell you the designer cared about strength without adding unnecessary mass.
Bad ribs tell you they tried to fix structural problems by “just making everything thicker.”
Material clues
Texture, stiffness, sink, warp, they’re all quiet indicators of resin choice, cost pressures, cycle time targets, and whether the material was tested or just “selected.”
Every part is a story. Every choice leaves a fingerprint.
And if you want to grow fast as a product design engineer, start studying the parts around you.
You’ll learn more than most textbooks ever teach.
What’s the first thing you look for when you pick up a part?