Wooden deck designed entirely of industrial pallets which are a stronger, more durable pallet. The spaces are filled with 1x boards cut to fit.
Complete Pallet Terrace
I did not count exactly how many disassembled pallets I've used to made this terrace (between 30 and 40). For the deck alone, I used 12 entire repurposed pallets. It costed me 50 €/$, and 1.5 months of work.