GG

"Gut genug", the greatest German insult, meaning "good enough".
Used in engineering circles, to tell someone to stop chasing perfection and wasting time.

Perfectionist: What do you think of this piece?
Person 2: Not bad, it's GG for a first try.
Perfections: *gasps audibly*

or

Engi 1: Should we redo the work and improve it?
Engi 2: Nah, it's GG, it'll work.

or

Engi 1: Our latest laptop design is only going to work for 2 years and 3 months before it breaks.
Engi 2: GG, it's over the warranty period. Ship it.