Download to read offline
FP adoption at REA
- 1. FP adoption atREA A human-first approach @KenScambler
- 5.
- 6.
- 9.
- 11. • ~150 developersin Melbourne • ~100 TW consultants in China • ~90 in Malaysia • Handful in Singapore, Thailand, Indonesia
- 12. 2013 2014 20152016 2017 Teams using Scala
- 13. 2013 2014 20152016 2017 Scala codebases 100 0 50 1 7 17 38 91 Total codebases: ~5200 ~2% are Scala
- 14. Beyond Scala Of 858public channels: • #28 all-time messages • #28 total members • #32 users posting messages
- 15. Weekly FP Guildsession 2013 2014 2015 2016 2017 0 50 10 15 18 25 Attendance/week 10 20 30 40 4 15 14 17 … Different presenters
- 16. YOW Lambda Jam2017 C◦mp◦se :: Melbourne 2017
- 18.
- 19. SOFTWARE COMPANY • Solvemy problems • Help me do what I do • On time • Supported Customers Real world Software
- 20. Customers Users SOFTWARE COMPANY • Easyto use • Make my life easier • Reliable
- 21. Customers Users Management • Bottom line •Hiring? • Long term view • Org health • Manage risk
- 22. Customers Users Product Managers • Verifyassumptions • Features! • Time to market Management
- 23. Customers Users Product Managers Management • Sleepat night • Visibility • Uptime, security, latency, performance, etc Site Ops
- 24. Customers Users Product Managers Management • Determinism •Reproducibility • Confidence Site Ops QAs
- 25. Customers Users Product Managers Management • Dogreat work • Solve problems • Feel productive • Learn!Site Ops QAs Developers YOW
- 26. Customers Users Product Managers Management Site Ops QAs THECODEDevelopers YOW
- 27. Tech is ok,but nothing makes sense unless it makes people’s lives better YOW
- 28.
- 29.
- 30. • Input Output • Less moving parts • Less coupling • Fewer possible incorrect programs • Better separation of concerns THE CODE
- 31. THE CODE • Canactually know things about the code • Refactoring is easier! • Great code reuse • I’m learning! Developers YOW
- 32. THE CODEDevelopers YOW QAs • Sameinput gives same response! • We can reproduce things
- 33. THE CODEDevelopers YOW QAs • Rarelyfails, in well understood ways • I can sleep Site Ops
- 34. THE CODEDevelopers YOW QAs • Devscould painlessly bolt my features on that old codebase! • I don’t hear “no” as often Site Ops Product Managers
- 35. THE CODEDevelopers YOW QAs Site Ops ProductManagers Management • Great for hiring! • Vibrant, energetic team • Microservices mitigate risk in tech choice
- 36. THE CODEDevelopers YOW QAs Site Ops ProductManagers Management Customers / Users • Reliable! • Regular updates
- 37. Tech choices areimportant because they can make people’s lives better YOW
- 38.
- 39.
- 40. Alan Turing Turing machines AlonzoChurch The Lambda Calculus Programming languages existed before computers did
- 43.
- 44. Fundamental software principles Applicability VS Last week’shot web framework Every single day Every language Every problem Every context Next 6 months, if you’re lucky Substance Eternal and unchanging fabric of the universe Eternal hamster wheel of memorising steaming piles of human error Long-term consequence Happiness, productivity & wisdom Quit and become a dentist like Mum always wanted
- 46. ...It would bea mistake to characterize lambda calculus as a universal language, because calling it universal is too limiting. Phil Wadler
- 47. @ FP Guild, teamdojos Chat channels Shared norms Central expert group #
- 48. shared norms iOS shared norms sharednorms shared norms Weekly guild meetings #functionalprogramming
- 49.
- 50. advice code review articles support secondmenttraining sessions sharednorms shared norms shared norms Central expert group
- 51. Should my teamuse Scala? Hey do you mind helping out with some advice for my team? We’re thinking about using Scala for the new service… Sure!
- 52. Maybe We’ve got acouple of Scala devs, and the rest of the team is keen. We want more maintainable assets. I can pay for an up-front learning curve. Maybe. Here’s some options, tradeoffs etc...
- 53. We have tightdeadlines, a new team of junior Ruby programmers, multiple stakeholders, and half our team is in Xi’an. I heard Scala will make us more productive. How can I make them like it? ABSOLUTELY NOT
- 54. Good signs Badsigns • Stable, established team • Existing FP/Scala experience • Project can bear learning curve • Good sentiment • Local developers • Realistic expectations • Unstable team • Nobody knows Scala/FP • Very tight deadlines • Mixed or negative sentiment • Offshore developers • “It’s the cool new thing” • “We’ll be immediately more productive”
- 55. Case study 1:Colliding teams Chalk Services Cheese Experience
- 56. Time for are-org! You are now the “Chalk & Cheese Dept”
- 57.
- 58. The hell amI even looking at
- 59. Seriously, I’ve been doingthis for 10 years and now I can’t do anything
- 60. Oops! Let’s scaleit back a notch.
- 61.
- 62. 6 months later… Oof.This is all going a bit slower than we thought… Not going to lie, this Scala/FP stuff is tough Is this really the right approach for us? Hmmm.
- 63. We have to helpour teammates! I’ll make tutorials… I’ll run a weekly training session!
- 64. 6 months later…Success! Woohoo! Productivity! This software is rock solid! Love it! Devs are knocking down the door to join. Great results. Future though?
- 65. Case study 2:Decay & drift Time for something new! Let’s use Scala
- 66. Can you helpus with some weekly training sessions? Sure!
- 68. 6 months later…turnover!
- 69. What do wedo with this thing?
- 70. I never really wantedthis tbh Me neither
- 71. Case study 3:Empathy FTW ? We do a lot of maintenance, quality matters. A lot of our stuff is already Scala. We really want to learn. I’m happy to invest in our skills!
- 72. Sure, I canfit you in once/week! Could you help us with some training?
- 73. It’s up tome to make sure my teammates are having a good time with this
- 74.
- 75.
- 76. val modifyBanana(b: Banana): Banana= ???Oh man. Struggling. Let’s slow down! I’ll help out.
- 77. Weekly survey How areyou finding it? 1 5 etc 1 5 Can you use technique X in anger? Let’s keep track of out progress, to work out how we’re doing!
- 78. val modifyBanana(b: Banana): Banana= ??? Still struggling. You’re doing great! We’ll all help
- 79. 6 months later…success! Project was a success! Well done team! We’re really happy with this code! We’ve levelled up!
- 80.
- 81. Antipattern 1: Underthe rug I’m going to lose my hipster badge at this rate
- 84. Haskell in prod, LIVINGTHE DREAM BABY!!!
- 88. Where did thiscome from?? I never would have agreed to this! It looks weird and we didn’t sign up for this
- 89.
- 90. Profunctor optics! Church-encoded free monad.Left Kan extension enriches our algebra into a functor…..etc Why on earth would we care about all that? Tense, fragile situation…
- 91. Soon enough… Howdyfolks I’m the new CTO! I’m really excited to….GOOD LORD what is going on there
- 94.
- 95. Antipattern 3: Flockof seagulls Can you folk help us out? AgileConsultyCorp Sure can!
- 96. This will never do! Let’sadd some AgileConsultyCorp pizzazz!
- 100. FP Guild Every Wednesday4pm without fail f ◦ (g ◦ h) = (f ◦ g) ◦ h
- 101. 2014 f ◦ (g◦ h) = (f ◦ g) ◦ h 4x
- 102. 2015 (theory) f ◦ (g◦ h) = (f ◦ g) ◦ h 15x (12x first time speakers)
- 103. 2016 (theory)f ◦ (g◦ h) = (f ◦ g) ◦ h 14x (6x first time speakers)
- 104. 2017 f ◦ (g◦ h) = (f ◦ g) ◦ h (theory)17x (7x first time speakers)
- 105. Low bar • Timeboxto 2 hours prep, max • Lower bar means more speakers • More diverse speakers • Sanity for organisers
- 106. Consistency “The show doesn’tgo on because it’s ready; it goes on because it’s 11:30.” - Lorne Michaels, SNL creator
- 107. Consistency • Consistency isreally important for building confidence in a group • Every Wednesday 4pm without fail, 4 years running • (except for Christmas & Hackathons)
- 108. Consistency 1. Call fortalks on Monday 2. Pester individuals 3. Riff on something off the top of head 4. Watch video Fallbacks:
- 109.
- 110.
- 111.
- 112. Variety Same thing… Week-to-week varietyin speakers & topics is important!
- 113. Look after beginnersand the experts will look after themselves
- 114. Blah blah monadstack, typeclass coherence I’ll bet I’m the only person who doesn’t understand this Imagined:
- 115. Blah blah monadstack, typeclass coherence I’ll bet I’m the only person who doesn’t understand this Actual: I’ll bet I’m the only person who doesn’t understand this I’ll bet I’m the only person who doesn’t understand this I’ll bet I’m the only person who doesn’t understand this I’ll bet I’m the only person who doesn’t understand this
- 116. • Natural biastoward advanced talks • Encourage beginner talks • Encourage beginners talking! • Bigger, more diverse crowds
- 117. • Functional programmingis totally awesome • Technical benefits are worth pursuing • None of it matters a damn unless you can make it help people • By taking a human-first approach, a sustainable, self-perpetuating culture of learning and achievement is possible, to everyone’s benefit Conclusion