I didn't implement a CNN from scratch, but a few years ago, I wrote a blog post on CNNs [1] because, like the other commenters, I could find almost no decent blog content on what exactly a CNN was. Maybe it will help in your efforts.

[1] http://gregorygundersen.com/blog/2017/02/24/cnns/

this seems really good. I always like to read code cause it gives a better idea how things works under the hood. when I first wrote a toy neural network I read everything I could on the topic, plus I was taking a ML class where the teacher was a big fan of implementing things from scratch.

If you want to implement a CNN from scratch, wouldn't you prefer an article that describes how it works, rather than an article that just gives you the code? Otherwise it's more a process of copying from a source moreso than implementing from scratch.

I guess you could look at a popular framework such as pytorch and try to figure our from the code how cnn is implemented