A propulsion system for an aircraft includes an electric propulsion engine configured to be mounted to the aircraft at an aft end of the aircraft. The electric propulsion engine includes a fan rotatable about a central axis of the electric propulsion engine. The fan includes a fan shaft mechanically coupled to a power gearbox. The electric propulsion engine also includes an electric motor having a driveshaft, with the electric motor coupled to the power gearbox through the drive shaft. The electric motor rotates the fan through the power gearbox. The driveshaft includes a flexible element for accommodating a misalignment of the electric motor and the power gearbox.