Launch your EC2 EBS instance with two SSDs on the second and third slots (after the root EBS volume), with this in your userdata:
#!/usr/bin/env bash
umount /dev/xvdb
umount /dev/xvdc
apt-get install mdadm -y
mkdir /u01
cat > /etc/init/mount-ephermal-ssd.conf <<HERE
start on virtual-filesystems
script
# Attempt a short circuit mount - one of these works
# after a reboot
mount /dev/md127 /u01 && exit
mount /dev/md0 /u01 && exit
# It's possible this was a EC2 STOP/START - create everything from scratch
# Although we specify md0, the actual device may be md127 upon reboot!!!
yes | mdadm --create --verbose --force /dev/md0 --level=0 --raid-devices=2 /dev/xvdb /dev/xvdc
# Last chance
mount /dev/md127 /u01 && exit
mount /dev/md0 /u01 && exit
# Clean FS
mkfs.ext4 /dev/md0
mount /dev/md127 /u01 && exit
mount /dev/md0 /u01 && exit
end script
HERE
start mount-ephermal-ssd