This course helped me when I was studying Mathematical Economics. Gem!

a good catch, thanks!

Hadoop is still widely used in enterprises (especially in banks), if you have experience working with Hadoop ecosystems it is a big plus anyway.

Yes, that is the status quo.

There is also some trends:

https://trends.google.com/trends/explore?date=today%205-y&ge...

if you understand the window ranges, especially the default one there is no surprise at all

i would also recommend the wonderful https://modern-sql.com/