EMI Issue: Ringing in switch mode power supply layout (5V -> 3V3)
Switching nodes are very short which is a good thing. But I don't understand the stubs on the traces to the inductor, you should delete them along with the two additional GND vias. This is not very useful.

Even if there a GND layer, I would not make the orange planes goes under the inductors. Do the same for L1 as for  L2, nothing under the inductor. You would avoid any coupling.

I really think output capacitors are too high. Semtech recommand a typical 44µF and you're at 200µF. Try removing the 150µF capacitor.



Also try to increase GND vias of C11, C62 and C10, C42, with at least 2 GND vias each, because if you have 3A current, it will flow through only two GND vias but 6 power vias. Same for C4 decoupling cap, try at least 2 GND vias.

Edit: I really don't understand the use of a ferrite bead and snubber at the end of a SMPS. FB are more used to prevent a power rail to get noise back into the main power rail, for example with PLL power rail. But the voltage after une main inductor should be within noise tolerance, especially for a 3.3V rail.

You may have a ringing due to improper use of FB, look at LC resonant frequency on this Analog Devices' paper : http://www.analog.com/en/analog-dialogue/articles/ferrite-beads-demystified.html