Well written article with first principles in mind. I would like to mention that in the section where the author talks about placement there's a hiccup. When you place grid items with grid-column:start/end, start refers to the starting column line and end refers to the ending column line. Not the columns themselves. If you look at [1] you can see there's 3 columns but the ending is at '4'.

Funnily enough this doesn't apply to spanning.Notice here with grid-column:1/span 3 it spans the length of 3 columns. [2]

These details perfectly illustrate the authors excellent point of using named template areas and placing items semantically. I apologise if this is pedantic, I really did like the article.

[1]https://jsfiddle.net/9ewzLcrs [2]https://jsfiddle.net/9ewzLcrs/1/