闭门造车

bì mén zào chē

to work in isolation, ignoring reality

Character by character

闭bì
shut

门mén
door

造zào
build

车chē
cart

做产品不能闭门造车，要多听用户的意见。

You can't design products in a vacuum; listen to your users.

Tone: negative (criticism).

Building a cart behind closed doors without checking the road.

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