Code editor design
After almost a decade of programming, I design a coding editor that I thought we needed, did research, wrote problems and solutions. Transferred all that to the design of a coding tool, it's not much different from others but it's simple and everything that's wrong with others has been changed and improved for a better developer experience.
What I paid attention to is that it should not be too different because the developers want to know what they are doing. Without unnecessary things, pure matter.