not a very simple one with all the "labels" and "numbers" etc.
I understand this concern. I did have quite a large number of non-technical people do the Japanese version of this course (I have a big following in Japan), and they seemed to actually understand it based on the feedback I got.
The course itself doesn't use any code and is not very fast-paced compared to this article: it spreads out the material covered in this article in 17 pages and takes about 2-3 hours to read.
I wonder if this visual presentation of lambda calculus is your invention
It's my invention (spent a year tweaking the details) but was inspired by things like Scratch. https://scratch.mit.edu/
I totally agree, in fact I'm going to link this :) The point I wanted to make is that every feature requires a bit of refactoring like this, whereas React puts some structure.
I definitely agree that for a startup team, Github is making CS interview questions extinct. Even github itself claims so: http://ozmm.org/posts/who_we_hire.html - "at GitHub we hire "The Girl or Guy Who Wrote X," where X is an awesome project we all use or admire."
However, it is a different question if you are running a company like Google or Facebook. For instance, recently there was a news that Google received > 75,000 applicants and is looking to grow by more than 5000 employees this year. http://goo.gl/9fpkt
If you want to scale at this level, you won't have time to look at Github or similar sites for every candidate in detail. There will also be great candidates who have never published their code (although they might be the minority). To maintain hiring standards in this kind of situation efficiently, asking very difficult algorithmic questions might be the only way to go - at least you will be able to maintain the same hiring standards for 75,000 applicants.