diff --git a/README.md b/README.md
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+++ b/README.md
@@ -470,6 +470,7 @@ A small group of programmers wants to change how we code—before catastrophe st
 * [Jo Meenen](https://www.cutemachine.com/7-habits-of-highly-effective-people-summary/) - 7 Habits Of Highly Effective People Summary
 * [rondy](https://gist.github.com/rondy/af1dee1d28c02e9a225ae55da2674a6f) - Effective Engineer - Book Notes. **Bonus** see also [The Effective Engineer website](http://www.effectiveengineer.com/) and [Effective Engineer Blog](http://www.effectiveengineer.com/blog)
 * [A random quote](http://arandomquote.com/books/) - Short summaries of books / Great books summarized in 5 quotes or less
+* [Ayooluwa Isaiah](https://freshman.tech/philosophy-of-software-design-summary/) - (2021) Book summary: A Philosophy of Software Design 
 
 > Tools
 * [EPUB Converter](https://www.epubconverter.com/epub-to-mobi-converter/) - Free EPUB to MOBI Converter. **Alternative** : [Convert Files](http://large.convertfiles.com/converter.php)