I am writing to a friend of mine and I can't find a proper word to describe two language-learning courses in Duolingo.
As for the Duolingo German and Spanish courses, I find them to be ...
The message I want to convey is that I think that they took care of every detail while they were making them.
Would you simply say well-made? Is there a more proper term to use to talk about the act of caring about the details?
As with all adjectives, there are several options to choose from. You could for example use: "attentive" which means: "Paying close attention to something." - English Oxford Dictionary
Since you want to convey an attention to every detail, then perhaps you could try: "As for the Duolingo German and Spanish courses, I find them to be holistically attentive."
Another adjective that would work is: "meticulous" which means: "Showing great attention to detail; very careful and precise." - English Oxford Dictionary
In that case you could for example say: "As for the Duolingo German and Spanish courses, I find them to be wonderfully meticulous in both design and execution."
Note: I added "wonderfully" and "in both design and execution" since to some native speakers, the word "meticulous" has a slightly negative feeling.
