A core arrangement for a heat exchanger, the core arrangement comprising: a first core layer disposed along a first plane, and comprising: an inlet oriented along a first axis within the first plane; an outlet oriented along the first axis; a first core stage disposed in fluid communication between the inlet and the outlet, the first core stage comprising: a first upstream fluid intersection downstream of and adjacent the inlet, and comprising a first inlet continuation and a first bifurcation ; a first downstream fluid intersection upstream of and adjacent the outlet, and comprising a first outlet continuation and a first recombination; and a plurality of independent first core tubes fluidly connecting the first bifurcation to the first recombination; and a second core stage disposed in fluid communication between the first inlet continuation and the first outlet continuation, the second core stage comprising: a second upstream fluid intersection downstream of the first inlet continuation, and comprising a second bifurcation; a second downstream fluid intersection upstream of the first outlet continuation, and comprising a second recombination; and a plurality of independent second core tubes fluidly connecting the second bifurcation to the second recombination. an inlet oriented along a first axis within the first plane; an outlet oriented along the first axis; a first core stage disposed in fluid communication between the inlet and the outlet, the first core stage comprising: a first upstream fluid intersection downstream of and adjacent the inlet, and comprising a first inlet continuation and a first bifurcation ; a first downstream fluid intersection upstream of and adjacent the outlet, and comprising a first outlet continuation and a first recombination; and a plurality of independent first core tubes fluidly connecting the first bifurcation to the first recombination; and a first upstream fluid intersection downstream of and adjacent the inlet, and comprising a first inlet continuation and a first bifurcation ; a first downstream fluid intersection upstream of and adjacent the outlet, and comprising a first outlet continuation and a first recombination; and a plurality of independent first core tubes fluidly connecting the first bifurcation to the first recombination; and a second core stage disposed in fluid communication between the first inlet continuation and the first outlet continuation, the second core stage comprising: a second upstream fluid intersection downstream of the first inlet continuation, and comprising a second bifurcation; a second downstream fluid intersection upstream of the first outlet continuation, and comprising a second recombination; and a plurality of independent second core tubes fluidly connecting the second bifurcation to the second recombination. a second upstream fluid intersection downstream of the first inlet continuation, and comprising a second bifurcation; a second downstream fluid intersection upstream of the first outlet continuation, and comprising a second recombination; and a plurality of independent second core tubes fluidly connecting the second bifurcation to the second recombination. <EOS>