Just FYI building a pool also requires multiple contractors- masonry, steel and shotcrete, electrical, plumbing, tile, gas, plaster and more dependending on rock work(only ever worked with real), specified molds(slides, rivers) etc. All while scheduling around specific building progression.
Building is building and all building is very similar it is merely the size and scope that changes but the process is the same. Planning, designing, engineering, permits, grading, structure, etc.
As for this specific project please see
@Disneyhead he sums it up quite well.