It would be helpful to know if your car is stock, or if not what modifications to the suspension and wheels you have. Also, what tires do you have? Some tires ride considerably harder than others, and switching to a different tire can soften the ride somewhat.
My suspension is stock except for aftermarket wheels in stock size which are 5 lb lighter per corner then the stock wheels. That change in unsprung weight softened up the ride some, there is less weight banging up and down each time the wheel and tire go over a bump.
Just FYI Ford softened the ride for the Fiesta STs starting early in the 2016 model year, so the earlier ones rode harder. To some extent a stiff ride is a necessary side effect of the crisp and agile handling and quick turn in the car has. If you soften the ride too much you risk compromising that. I would live with it a bit and see if you get used to it before you make any dramatic changes, but you're doing the right thing asking about options on here, there are a lot of knowledgeable people who have done a lot of different things to their cars.