My wife and I just finished watching the behind-the-scenes videos of how the Mandalorian was made. It is a series of 8 videos on Disney+ that have the producers, directors, actors, designers, etc all talking about how they did it. Very interesting. Particularly fascinating is the use of what they call The Volume. It is a production set with lots of LED screens upon which the backgrounds and scenes of what they are filming on projected using gaming engine technology. They are using this to replace green screens in movie/video production. They focus on that in episode #3 of the behind-the-scenes video.

Here's a video from ILMFX (Industrial Light & Magic Special Effects) that talks about The Volume

https://www.youtube.com/watch?v=gUnxzVOs3rk