10 Big Ideas from Industry
1 like•183 views
The document outlines ten key ideas for software development, emphasizing the importance of version control, feedback cycles, and developer rights. It advocates for maintaining high-quality code while separating implementation from refactoring, and stresses the value of both object-oriented and functional programming. Additionally, it highlights the necessity for continuous skill development and effective social interaction within teams.
10 Big Ideas from Industry
- 1. [email protected] February 2019 © Instil Software 2018 10 Big Ideas from Industry Queens University
- 3. With Special Thanks to Liberty IT
- 4. I’m here to Raise Awareness
- 5. How I Got Started…
- 6. Ten Big Ideas From Industry…
- 7. These ideas are not mine • They are wisdom from experts in the industry • So I will be showing you a lot of Tweets from gurus As you know… • Copying from a single source is plagiarism • Copying from many sources is research J None Of These Ideas Are New
- 8. © Instil Software 2018 Version Control Matters (Unless you’re a masochist)
- 10. Learning About Version Control
- 11. Introducing Git 10 1 2 3 4 6 5 8 9 7 10 A Git repository is a complex tree and can present branches with individual history logs A branch is simply a pointer to a node
- 12. Introducing Git 10 1 2 3 4 6 5 8 9 7 10 This is possible because structurally every node refers to one or more parents The arrows drawn so far need to flip When we use branches and make changes, the pointer moves automatically
- 13. Introducing Git 10 1 2 3 4 6 5 8 9 7 10 Arrows now represent a dependency Our repository is actually a Merkle Tree
- 14. Introducing Git 10 1 2 3 4 6 5 8 9 7 10 We can also mark or remember individual nodes by adding tags Unlike branches, tags do not move R1.0.0 R1.0.0 R0.2.0 R0.2.0 R0.2.0 R0.2.0
- 15. © Instil Software 2018 Create Feedback Cycles (The smaller the better)
- 16. Find And Tighten Feedback Loops BEST TWEET EVER
- 18. Find And Tighten Feedback Loops
- 19. Find And Tighten Feedback Loops
- 20. Build faster feedback loops • Running unit tests every few minutes via TDD • Running integration tests every few hours via CI • QA teams completing non-functional tests weekly • Clients commenting on demos every 2-3 weeks • Releases measured in weeks or months Agile = Feedback Loops
- 21. TDD BDD Integration Tests / CI Non Functional Tests / QA Sprint Demos and Retrospective Feedback Cycles in an Agile Project
- 22. The Test Driven Cycle In Outline
- 23. Celebrate the ‘but that’s stupid’ moments! • This is what keeps us going the right way • Limitations of the current code inspire the next test Always watch the test fail first • The existing codebase may already do what you need • You may have accidently written a test that cannot fail Don’t implement and refactor at the same time • They are two separate activities • Mixing them only causes confusion • Remember tests need refactoring as well There’s a difference between simplest and stupid • Keep making progress towards your intended design • Never work yourself into a corner in the name of simplicity Key Points About the TDD Cycle
- 24. Understanding the TDD Cycle
- 25. Some Great Reads
- 26. Some Great Reads
- 27. © Instil Software 2018 Its OK To Be Scared (But never not to ask)
- 28. Programming Is Really Really Hard
- 29. No Fear (Well Just A Little) Pure Bowel Knotting Terror You’re Going To Experience Fear Every Day…
- 30. You have the right: • To know what is needed (requirements) with clear declarations of priority • To produce quality work at all times • To ask for and receive support from peers, superiors, and customers • To make and update your own estimates • To accept responsibilities instead of having them assigned to you The Developer Bill of Rights
- 31. You have the right: • To an overall plan, to know what can be accomplished when and at what cost • To get the greatest possible value out of every programming week • To see progress in a running system proven to work by passing repeatable tests that you specify • To change your mind, to substitute functionality, and to change priorities without paying exorbitant costs • To be informed of schedule changes in time to choose how to reduce the scope to restore the original date • You can cancel the project at any time and be left with a useful working system reflecting the investment to date The Customer Bill of Rights
- 33. © Instil Software 2018 Social Skills Matter (It’s a team sport)
- 34. Social Skills Matter Developers start out obsessing about code • But end up as psychologists and/or linguists Coding in industry shouldn’t be completely novel • All the really technical problems have been solved already People are a very different matter • The true challenges in software all revolve around people • Your colleagues, your management, your clients etc…
- 35. Not this… Or even this… But this…
- 38. © Instil Software 2018 Performance Matters (Except when it doesn’t)
- 40. What is Meant by ‘Performance’? ‘Performance’ can mean many things: • Latency – the time for an item to be processed • Throughput – no of items completed per ‘n’ • Scalability – how throughput alters as usage increases • Degradation – what happens when we can’t scale further • Utilization – making full use of cores, RAM etc... Each application will have its own priorities • E.g. an Android or iOS client will want low latency whereas a batch processing system will want high throughput
- 41. Examples of Relative Costs of Operations
- 42. How do we Measure Performance? We measure performance with: • Micro-benchmarks - fictional analysis of part of the system • Profiling - collecting runtime data from a ‘real’ system • Benchmarking - determining the limits of the ‘real’ system • Monitoring - collecting metrics from various environments The best measurements are the most difficult to obtain • The closer you come to real world usage the greater the barriers in your way to collecting measurements • In some environments there may be legal constraints that prevent you ever interacting with the system in production
- 44. Does Performance Matter? In the early days of IT performance was everything • Because hardware was expensive compared to developers Over time this began to change • Developer time became expensive compared to hardware • Software spent more and more time being maintained Developers understanding of performance declined rapidly • As the underlying platform became more and more complex Today the rule is: • Write the shortest simplest code you possibly can • Allow the compiler, VM and hardware to optimise it • Don’t constrain your code with assumptions about speed • Have performance tests to provide reliable feedback
- 45. © Instil Software 2018 Code With Two Hats (Wear one at a time)
- 46. There Is Some Truly Horrible Code Out There…
- 47. Real Developers Write Code That’s Readable
- 48. Good Boy Scout Rule
- 49. Refactoring Is Part Of Normal Development
- 50. Quality Feedback Loops Clearly Correct Code Ubiquitous Language Encapsulation Immutability Decomposition Verification Spec By Example OO FP Single Purpose Methods TDD BDD Profiling DDD RX Iterations CI TDD The limits of my language mean the limits of my world If you always do what you’ve always done you'll always get what you’ve always got “Obviously No Defects” Vs. “No Obvious Defects” Reviews Retrospectives DI Modules MVC Monads Structs Contracts
- 51. Read These Books
- 52. Never Implement and Refactor at the Same Time!!! We write code with ‘two hats’ • The ‘I have to get this ******** thing working’ hat • The ‘someday someone will maintain this’ hat The second hat is the Refactoring one • Refactoring is a vital skill in its own right Never implement and refactor together • Your thinking will get derailed and you will create a mess
- 53. Unit Tests And Refactoring Go Hand In Hand
- 54. © Instil Software 2018 Apply the S in SOLID (In a hierarchical manner)
- 56. The Single Responsibility Principle Every function / type / class you write should • Perform a single function in the app • Have only ever one reason to change • Be describable without conjunctions This is indicated by brevity • Aim for method lengths of 10 lines or less • Or even 6 lines or less in Ruby / Scala / Kotlin
- 57. SRP Works at Different Levels of Abstraction…
- 58. Unit Tests Are Tests Of Abstractions
- 59. © Instil Software 2018 Naming Is Everything (…and incredibly hard)
- 60. When It All Goes Wrong...
- 62. Get Into The Habit Of Worrying About Names
- 63. Introducing Domain Driven Design
- 65. Bounded Contexts and Language Games But how many kinds of sentence are there? Say assertion, question, and command?--- There are countless kinds: countless different kinds of use of what we call "symbols", "words", "sentences". And this multiplicity is not something fixed, given once for all; but new types of language, new language-games, as we may say, come into existence, and others become obsolete and get forgotten. (We can get a rough picture of this from the changes in mathematics.) Here the term "language-game" is meant to bring into prominence the fact that the speaking of language is part of an activity, or of a form of life.
- 66. © Instil Software 2018 Objects Are Awesome (But FP is the future)
- 68. Object Orientation Has Proven Its Worth…
- 69. Objects Threads
- 70. Functional Coding Is Becoming More Prevalent
- 71. Comparing the OO and Functional Styles
- 72. But all a purely functional program can do is heat up the CPU - and that's still a side effect!!!
- 73. Languages on the JVM Java Virtual Machine Bytecode Interpreters JRuby Groovy Jython Scala Clojure KotlinJava Gradle
- 74. Making Waves at the Moment
- 75. You Might Want To Learn Haskell…
- 76. © Instil Software 2018 The Jungle Is Neutral (So it’s all up to you…)
- 77. Routes Into IT & Career Progression • System Administrator • DB Admin • Network Admin • Remote Support • On-site Support • Professional Services • Junior à Senior Tester • Test Team Lead • Junior à Senior Developer • Technical Lead • Architect • Evangelist Dev QA Sys Admin CD Management Sales & Marketing
- 78. You need to keep updating your skill set • Frameworks go out of date every 2-6 years • Programming languages every 6-12 years You Need to Keep Your Skills Updated
- 79. You Need To Manage Your Own Career
- 80. Ultimately The Jungle Is Neutral…
- 81. © Instil Software 2018 In Summary…
- 82. Here are our 10 Big Ideas once again: • Version Control Matters • Create Feedback Cycles • It’s OK To Be Scared • Social Skills Always Matter • Performance Can Matter • Code With Two Hats • Apply The S In SOLID • Naming Is Everything • You Need OO And FP • The Jungle Is Neutral In Summary
- 83. Any Questions?