How this site began
As over the time when I worked with software and I used different technologies, as I was learning it, I first created simple code examples so that could I "touch" new stuff and also later quickly remind myself the principles when I needed them, because they evaporated, when I did not use them for a while. Later I found when getting back to "ready-to-compile" examples, it still took me some time to ramp up, so started adding brief comments. One day I found that the collection covers good part of knowledge that software developers and architects may need to quickly find and I realized that it could be useful for others as well, so as I am updating them, I am converting them to the format where they could be published.
What you can find here
Focused on technology fundamentals
This site is for developers with some experience. Content of this site focuses on technology knowledge and tries to minimize domain problems to minimum needed for the technology understanding.
Structured for efficient memorizing
The topics are structured in small snippets and each of them has Knowledge verification section to help check if what you remembered. You can use them also with Anki desktop and/or smartphone application to memorize the fundamentals. You need to save the file that will be imported, because it contains tabular characters to separate questions and answers.
80/20 rule applied to software development
You need know to 20% percent of the technology that you use to create 80% of the functionality for your app, meaning that the topics will mostly cover the most important parts that you need to start using particular technology with links to resources where you can find more information.