Simplicity matters

Transcript

1. Simplicity matters Pierre GOUDJO
2. Edsger W. Dijkstra Simplicity is a prerequisite for reliability
3. • Simple simp - plex one fold / braid vs complex
 • Easy ease < aise < adjacens lie near vs hard Etymology
4. • One fold/braid • One role • One task • One concept • One dimension
 • About lack of interleaving, not cardinality • Simple is objective Simple
5. Simple vs complex
6. • Near at hand • On our hard drive, in our toolset, IDE, npm install, apt get, gem install… • Near to our understanding/skill set • Familiar
 • Near our capabilities • Easy is relative Easy
7. • We can only consider few things at a time • Making a system reliable implies understanding it • Complexity undermines understanding Limits
8. • Emphasising ease gives early speed • Ignoring complexity will slow you down over the long haul Development speed Productivity Time Simple Easy
9. • Essential complexity • Inherent to the domain you are working on • Essential to the user’s problem
 • Accidental complexity • Not related to the domain • Entanglement of ideas/ components not necessary for solving the problem Complexity
11. Rocket control software • Complex domain • Possibly complex software Example
12. Inherent Complexity • Usually means reducing the problem space • Leads to more focused software • Lean Product Management can help focus on the real value Reducing complexity
13. Law of conservation of complexity — Larry Tesler Every application has an inherent amount of irreducible complexity. The only question is who will have to deal with it —the user, the application developer, or the platform developer?
14. Accidental complexity • As developers, we should focus our attention here • Leads to less bloated software • Less accidental complexity => Understandable software Reducing complexity
15. Out of the tar pit — Ben Mosely, Peter Marks Simplicity is hard
16. Making things easy • Bring to hand by installing • Become familiar by learning, trying • Mental capability? • Not going to move very far • Make things easy by simplifying them
17. We can be creating the exact same programs out of significantly simpler components
18. Simplicity Toolkit Complexity Simplicity State, Objects Values Methods Functions, Namespaces vars Managed References Inheritance, switch, matching Polymorphism and composition Imperative loops Set functions Actors Queues ORM Declarative data manipulation Conditionals Rules Inconsistency Consistency
19. • To place together • Composing simple components is the key to robust software • Partitioning and strati fi cation don’t imply simplicity • But are enabled by it Composition
20. Tony Hoare — Turing Award speech 1980 ...there is one quality that cannot be purchased... — and that is reliability. The price of reliability is the pursuit of the utmost simplicity
21. Agile Manifesto Simplicity—the art of maximizing the amount of work not done—is essential.
22. Not doing the work and offloading decisions to third-party dependencies doesn’t reduce the complexity of the application
23. Programmers vs Programs • We focus on ourselves • Programmer convenience • Programmer replaceability • Rather than the programs • Software quality, correctness • Maintenance, change
24. Rich Hickey Programmers know the benefits of everything and the tradeoffs of nothing
25. Simplicity is a Choice • Requires vigilance and care • Equating simplicity with ease is wrong • The focus should be around entanglement not easiness
26. Leonardo de Vinci Simplicity is the ultimate sophistication