Notes for understanding how software works.
Diary Coding is maintained by Putu Adi Guna Permana to share programming and application security notes.
Who is this site for?
This site is for learners and developers who want to understand the reasoning behind an implementation: how access decisions are made, how data is processed, and how to check the outcome of a change. Our original guides focus on programming and application security.
Start with a concrete problem
Use search and topic categories to find a relevant guide. For application security, start with API authorization, separating data from SQL query structure, and browser output handling. Lab examples use synthetic data; they do not claim customer-system testing or establish that an entire application is secure.
Author and sources
Putu Adi Guna Permana is the author and founder of Diary Coding. Each article identifies its author. Articles from other publishers are grouped in the source-attributed reference library, separate from original guides. Republished news also retains its source and licensing information.
Help improve the guides
Examples can change as software versions evolve. Report unexpected results, explanations that need correction, or broken links through the contact page. Include enough context for the problem to be investigated.