As object oriented programming starts to fall out of favor with developers, functional programming is making a comeback. Reasons such as side effects and unit testability are hastening it. The Telerik developer blog has a great post up detailing functional programming with arrays.
The VS Code team has a really good article around their Text Buffer Reimplementation in the latest version. There is a lot of good information around performance and the implications of certain design patters revolving around file size.