Add content to complexity in software design part

lectures/complexity/slides.qmd

@@ -137,20 +137,49 @@ These can come with **very** different complexity ratings.
 For certain tasks (e.g. sorting, neighbors, averaging, or really anything...), think about what complexity class is expected.
 If your program behaves differently, **change it** or **seek advice** from colleagues.
 
-# Complexity in software design
 
-## interdependence of components
 
-possibly also amount of coordination and communication needed
+# Complexity in Software Design
 
-## ways to counteract
+::::::::{.columns}
+
+:::{.column width=50% .smaller}
+
+_"Complexity kills. It sucks the life out of developers, it makes products difficult to plan, build, and test"_
+
+Ray Ozzie, former Microsoft CTO
+
+:::
+
+::::::::
+
+
+## Interdependence of Components
+
+Here complexity refers to
+
+ - amount of interactions between objects
+ - resulting amount of coordination and communication needed
+
+Complexity is not about complicated designs
+(although simple designs are usually a good idea)
+
+
+## Typical Ways to Counteract
+
+- Use abstraction when suitable
+- Encapsulate different concepts in different objects/classes/...
 
-- Abstraction
-- Encapsulation
 
 ## Maintainability
 
-_Also focus on maintainability. This lecture might or might not be the right place, but it should be useful somewhere_
+**If code works, why put more effort in it to reduce complexity and make it more approachable?**
+
+ - Your future self and others can understand faster,
+ - Changing and adding components should be easy and only require local adjustments,
+ - Bugs are easier to find when the complecity is low (and components individually testable),
+ - This also makes testing easier and more likely to test all code paths (high code coverage)
+
 
 # Resources