During the VK Education codecamp a main tasks were code refactoring and adding new functions for special projects.
Different companies needed different API methods and functions for their goals. Moreover, it was necessary to flexibly manage access rights. I transfered all the methods used by special projects to a new section of API and rewrote unified rights management system for them. Also, I added some functions & changed Callback API methods for new projects.
Another key issue was ads targeting on mobile devices. A lot of Android devices could't be defined in their price category and targeting worked much worse for them. I increased the accuracy of ads targeting in several times by distributing thousands of unique devices by price category.
Unfortunately, due to the NDA, I cannot show the code, but it's pretty good because of 3+ reviews every Pull Request :)

How I built it

VK uses its own PHP — kPHP. It compiles to C++ and works very fast and also has static typing.
Moreover, I have worked with Python & MySQL and a lot of servers.

Additional Stories

One day I made a mistake in the name of variable and almost broke everything 😅