Things We're Used to Seeing...
... But still amazed by: designed for 5 flights, got 28 in the log book.
There's fewer and fewer refuges in which what one might call "proper engineering" is still done, but the space exploration programme is still one of them.
I know that the exploration of Mars has in recent times been "Agile" in the sense that one mission has lead to another better mission, but they're not making many mistakes.