What I did for this video was put together all the individual images, or coding videos. Like the pictures of code, screenshare footage and some animated gifs from online.
I made a script where I described at each step, like, "Show this code", "put this word on the screen." with second by second transcripts. I did my best to describe it in prose on a second by second timeline of the video what we should see.
Then we used an editing company who put together a version of that and we iterated with some back and forths.
Long story short, besides choosing from existing animations, they did everything that moves. I made the static resources and they animated it all together.