The first 90% of the code accounts for the first 90% of the development time. The remaining 10% of the code ac... — Tom Cargill

The first 90% of the code accounts for the first 90% of the development time. The remaining 10% of the code accounts for the other 90% of the development time.

Author: Tom Cargill

Insight: That final 10% is where perfectionism lives—polishing edge cases, fixing bugs nobody sees, making sure nothing breaks. It's why your project feels done at 80%, then somehow takes twice as long to actually finish.

Source: 'Programming Style', Bell Laboratories, 1985