The document discusses the concept of simplicity in software development. It states that simplicity is essential according to agile principles and that complexity is the silent killer of delivering software on time. It defines simplicity as the absence of complexity and discusses various sources of complexity such as dependencies, state, mental strain, libraries, frameworks, programming languages, and more. It provides recommendations for achieving simplicity, including test-driven development, modularity, pure functions, minimizing dependencies, and choosing libraries wisely.

1. simplicity
.demystified
osvaldas grigas
@ogrigas | ogrigas@gmail.com

2. inspired by
Dan
North
Rich
Hickey

3. Computing's central challenge,
"How not to make a mess of it",
has not been met.
Edsger Dijkstra
(1980)

4. what "simple" ain’t ...
familiar / convenient
small / concise
beautiful / elegant

5. "nothing is more simple than a single giant button"

7. from the agile principles
“Simplicity -- the art of maximizing the
amount of work not done -- is essential.”

8. from the agile principles
“Simplicity -- the art of maximizing the
amount of work not done -- is essential.”
YAGNI

9. from the agile principles
“Simplicity -- the art of maximizing the
amount of work not done -- is essential.”
YAGNI

10. from the agile principles
“Harness change for the
customer's competitive advantage.”

11. Complexity is the silent killer of
delivering the right software,
or change, at the right time.
Russ Miles

12. from the agile principles
“Technical excellence and
good design enhances agility.”

13. Design is there to enable you to
keep changing the software easily.
Martin Fowler

14. from the agile principles
“Developers should maintain a
constant pace indefinitely.”

15. Once your software is of a
certain size, complexity is gonna
dominate what you can do.
Rich Hickey

16. ultimate definition of simplicity

17. ultimate definition of simplicity
simple == not(complex)

18. complexity
.demystified
osvaldas grigas
@ogrigas | ogrigas@gmail.com

19. mixed responsibilities

20. dependencies
& coupling

21. state
& side effects

22. mental strain

23. essential
complexit
y

24. tal
den
nci
i
xity
ple
com
essential
complexit
y

25. y
code
our
essential
complexit
y

26. rie
s
lib
ra
& frameworks
y
code
our
essential
complexit
y

27. lib
ra
rie
s
& runtime
ge
ua
ng
& frameworks
la
y
code
our
essential
complexit
y

28. complexity brought by
your code
supported by:
oring
fact
re
ools
t
autoimport
code
generators

29. complexity brought by
libraries
supported by:
gem
nuget
maven

30. complexity brought by
frameworks
ORM
WEB
IoC

31. the law of leaky abstractions

32. complexity brought by
the programming language
inheritance-based design
unconstrained mutability
lack of expressivity

33. making things
simple

34. TDD, BDD
& refactoring

35. modularity

36. use values
and pure functions

37. minimize direct dependencies
introduce indirection
follow the law of demeter

38. single responsibility principle
& composition
wget -qO- http://c2.com/ | tr -cs '[:alpha:]' 'n' | sort | uniq

39. be ignorant and oblivious

40. choose libraries wisely
“We choose Camel over Spring-Integration
because the fluent API is really nice.”
accepted answer

41. prefer libraries over frameworks

42. step out of your comfort zone