This is a personal, living compendium of things I’ve learned, figured out, tripped over, or decided I really needed to remember later. It lives somewhere between a notebook, a reference manual, and a set of field notes. Think of it as less a polished encyclopedia, more a map of practical knowledge accumulated over time. Some knowledge is distilled into blog posts at mattiselin.com. This codex holds the rawest form of that knowledge.
Content here is intentionally uneven in scope and depth. Short stubs will capture a single useful fact or workaround. Longer pages might be devoted to longer explanations that emerged after repeated encounters with the same problem. Not everything is complete, and not everything is final. Accuracy and usefulness matter more than completeness or elegance.
The purpose of the Codex is simple: to externalize my hard-won discoveries so they don't evaporate, and to make it discoverable for myself and for anyone else who happens to stumble upon this knowledge base.
Consider it a working library.