Brunelleschi made the bricks hold each other up
Florence's cathedral had stood without a roof for over a century because no one could figure out how to close an octagonal hole 140 feet across. The man who finally did it used no central scaffolding at all.
The dome of Santa Maria del Fiore in Florence was completed in 1436, but the problem it solved had haunted the city for generations. The base of the drum was too wide for any known wooden scaffold to span — there wasn't enough timber in Tuscany. Competitors proposed filling the whole interior with a mountain of earth laced with coins so workers would dig it out afterward. Filippo Brunelleschi had a different idea.
He laid the bricks in a herringbone pattern — called spina a pesce, fishbone — so each section leaned against its neighbors and locked into a rising spiral. As each course closed, it held its own weight before the mortar had cured. The dome was self-supporting from the first ring to the lantern, built in a double shell that spread the load outward and down into the drum.
When builders ask how a structure can be assembled before it exists, this is one answer: design the process of construction so that each completed part becomes the scaffold for the next. The finished object isn't a noun that appears at the end. It's a verb the whole way up.