All I can say, if you make it to the last episode, stop before the last scene. Actually, once the Universe is saved, don’t go any further.
SPOILER ALERT
Part of the premise of the last two seasons is that catestropic event has fractured The Federation. Even Earth isn’t a member anymore. Of course the USS Discovery saves the universe and all the planets rejoin the Federation.
SPOILER ALERT
In the last scene the President of UNITED EARTH, read that as a one world government, The President, Stacy Abrams, comes aboard Discovery to thank everyone. Stacy Abrams? Really?