The last ten percent of any project is where most of the work was hiding.

Progress feels fast while the big pieces go in and then crawls near the end, which is not a failure of energy. The final stretch is made of small awkward problems that were invisible at the start: the fiddly parts, the checking, the things that only appear once everything else is in place. It always takes longer than the estimate because it was never inside the estimate.

Budget extra time for finishing rather than for building. When it drags, that is normal rather than a sign you chose wrong. Push through the small stuff and it becomes real.