The case and keycaps were designed in Fusion 360 and were printed on an Elegoo Mars 2 resin printer. Because of its dimensions, the case was printed in two parts which were resin welded together.
The overall printing time was around 20 hours.
Resin welding
According to BeniBice, the most important thing is that the two edges you want to weld fit each other well. This can be difficult due to the warping of the print. The author's solution was to print the edges at an angle of 15° degrees on two axes with medium sized supports (results):
Put some resin on the edges you want to weld. Don't apply too much at first, as it is hard to clean the excess resin off. (u/BeniBice also doesn't cure the parts until after welding.)
Firmly press the two parts together and harden the resin with a UV flashlight for a couple of seconds until it holds temporarily.
(Carefully fill the holes, if you have any.)
Cure the model as usual.
Applying what you've learned might get you a model you can barely tell apart from one that was printed in once piece.