In 1984, a young materials engineer named Glenn Culbertson started his career at GE Aerospace in Evendale, Ohio. Like every new hire, he was drowning in introductions, org charts, and conflicting advice about who he really worked for.One day, an old-timer pulled him aside and dropped a line that cut through all the noise:“A lot of people will tell you that they’re your customer: your boss, your boss’s boss, the CEO. They’re all wrong. The customer is the engine. If you do right by the engine, you’ll do right by everybody else.”
Forty years later, that single sentence still feels like gospel.
The Engine Doesn’t Lie
PowerPoint slides can be massaged. Schedules can slip. Budgets can be renegotiated. But a turbine disk spinning at 12,000 rpm and 1,300 °C doesn’t care about your feelings, your title, or how well you networked at the leadership offsite.
It will either stay in one piece for 30,000 flight cycles or it won’t.
The coating will either survive the sand ingested over the Arabian desert or it won’t.
The blade will either clear the rub strip by two mils under the worst-case thermal growth or it won’t.
There is no spin doctor for a containment failure at 35,000 feet.
When the hardware is your ultimate customer, truth becomes non-negotiable. You can’t “manage expectations” with a fractured fan blade. You can’t “circle back” with molten metal.
The engine delivers the verdict instantly and without mercy.And strangely enough, that merciless honesty is liberating.
The Invisible Promotion Machine
A part that lasts twice as long in the engine saves the airline hundreds of millions in maintenance costs.
A coating that survives 50% more cycles delays a shop visit by years.
A design margin you fought to protect prevents a fleet-wide grounding.
Those are the kinds of contributions that get remembered when the CEO is on the phone with a furious airline chairman at 2 a.m. And when the crisis is over, nobody forgets who kept the engines turning.
Do right by the engine, and the promotions, raises, and corner offices tend to take care of themselves.
A Principle Bigger Than Aerospace
I’ve heard almost identical versions of this advice in other places:
At Tesla, some veterans say “The customer is the car.”
At SpaceX, it’s “The customer is the vehicle.”
A legendary Toyota sensei once told a room of American engineers: “The customer is the product. The product does not speak English, but it always tells the truth.”
The wording changes. The meaning doesn’t.When you treat the thing you’re building as the ultimate stakeholder, you stop optimizing for short-term optics and start optimizing for reality.
You ask harder questions. You push back on bad ideas—even when they come from three levels above you. You stay late not to impress your boss, but because a fatigue crack doesn’t care what time the cafeteria closes.
Put It on the Wall
If you’re an engineer, a designer, a coder, a founder—anyone who builds things that have to work when real stakes are on the line—steal this line.Print it out. Tape it above your monitor. Make it your team’s unofficial motto.“The customer is the engine.”
(Or the rocket. Or the software. Or the bridge. Or the medical device.)
Do right by that thing, and you’ll do right by everyone else.The hardware never lies.
And in the end, it’s the only customer that can make or break your career.
Product alone emits right signals!
Everything else is just noise.