Improving Developer Experience Through Tools and Techniques 2022

Transcript

1. Improving Developer Experience
   or "How to save hours of development 4me each week?"
   by @merowing_ 1
   

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2. I've been focused on developer experience for more than a decade
   by @merowing_ 2
   

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3. Improving Developer Experience
   Is it one of the best investments we can make?
   by @merowing_ 3
   

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4. Good Developer Experience allows us to
   • Focus on user/business goals
   • Provide efficient workflows
   • Keeps us engaged with the work we are doing
   • Work smart, not hard
   • Limits human mistakes
   by @merowing_ 4
   

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5. How can we improve Developer Experience?
   by @merowing_ 5
   

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6. How can we improve Developer Experience?
   • App architecture
   • Removing required manual steps
   • Workflow and code automa;on
   • Building developer tools
   • Shortening feedback loops
   by @merowing_ 6
   

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7. How to gauge if you should invest 3me into tooling?
   • Is this inconvenient just for me?
   • Do other folks in my team run into the same kind of problems?
   • How o=en does it happen?
   • What's the total team @me per week wasted on this problem?
   by @merowing_ 7
   

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8. How to gauge if you should invest 3me into tooling?
   • NYT project used internal / 3rd party tools with each build
   • The total on each build adds about 6s, only 6s, right?
   • I measured that I build between 200-400 Dmes daily, and 90% of
   the Dmes we don't need those tools to run again
   • We had ~30 iOS developers touching the main app
   • Lower threshold = 200 $mes * 6s * 30 devs * 90% => 9 hours
   wasted per day
   by @merowing_ 8
   

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9. How to gauge if you should invest 3me into tooling?
   • This means we were was-ng 45 hours per week.
   • If we can improve that, it's almost like hiring a new full--me
   developer, except it's free.
   • Is it worth inves-ng -me to improve it?
   •
   ✔
   Definitely
   • How to do it? Custom pre-process script on pre-commit / CI
   • Read more @ my blog h4ps:/
   /bit.ly/3uwbqhL
   by @merowing_ 9
   

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10. Common Issues
    and things we can do to improve our projects
    by @merowing_ 10
    

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11. Issue - Manual Steps
    by @merowing_ 11
    

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12. Issue - Manual Steps
    Need to fill out some fields? e.g., login creden4als
    • Use user breakpoints
    • Data never leaves your machine
    • Easy to disable
    by @merowing_ 12
    

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13. Issue - Manual Steps
    Are you working on a long-running feature?
    by @merowing_ 13
    

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14. Issue - Manual Steps
    Are you working on a long-running feature?
    • Build-phase script that allows you to create #if branches per
    developer (e.g., h;ps:/
    /bit.ly/3mmfLRP)
    #if merowing
    showARExperience(StubARData(...))
    #endif
    by @merowing_ 14
    

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15. Issue - Retain Cycles
    by @merowing_ 15
    

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16. Issue - Retain Cycles
    Apple: Xcode Memory Graph Debugger + Leaks Instrument
    • Do you trust people will always run those tools and analyze their
    results before submi7ng Pull Requests?
    by @merowing_ 16
    

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17. Issue - Retain Cycles
    Open Source: Life'meTracker
    • How many instances of class X should
    ever be alive?
    • Works in Swi< and Objec?ve-C
    • Surface new retain cycle as you create
    them, not afeature
    by @merowing_ 17
    

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18. Issue - Retain Cycles
    Open Source: krzysztofzablocki/Life3meTracker
    Straigh(orward integra/on:
    class SectionFrontViewController: UIViewController, LifetimeTrackable {
    static var lifetimeConfiguration = LifetimeConfiguration(maxCount: 1, groupName: "SF VC")
    override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: Bundle?) {
    super.init(nibName: nibNameOrNil, bundle: nibBundleOrNil)
    /// ...
    trackLifetime()
    }
    }
    by @merowing_ 18
    

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19. Architecture integra-ons - e.g. TCA
    by @merowing_ 19
    

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20. Issue - Data dependencies
    by @merowing_ 20
    

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21. Issue - Data dependencies
    • Design your processing like a pipeline
    • Protocol at each stage, so it's easy to change
    by @merowing_ 21
    

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22. Issue - Data dependencies
    • Wri%ng tests for your ViewModel?
    • Bug report requires specific data?
    • Replace Model Converter with Fake Models
    by @merowing_ 22
    

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23. Issue - Data dependencies
    • Do you want to see how your whole applica3on reacts to specific
    data changes, but the backend isn't ready?
    • Easily load external data to the applica3on
    • In simulator ? loading from a local file would be preferred
    • On device? we need to load from a network server
    • We need real-3me updates
    by @merowing_ 23
    

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24. Issue - Data dependencies
    Open Source: KZFileWatchers
    • Works in Swi, and Objec4ve-C
    • FileWatcher.Local is useful for observing local file changes
    e.g., observing files on the developer desktop.
    • FileWatcher.Remote can be used to observe files on the
    web. Both Etag headers and Last-Modified-Date are
    supported.
    by @merowing_ 24
    

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25. Issue - Data dependencies
    -> Replace DataProvider with FileWatcher
    by @merowing_ 25
    

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26. by @merowing_ 26
    

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27. Issue - Data reproduc/on
    Can't reproduce bugs because your data changes o3en?
    • Every app deals with raw NSData at some point in the pipeline
    • Pipe it through (Identifier, Data) -> Data
    • Use only returned data:
    • If the app is in recording mode, it persist data in cache
    • If you are in reproduc=on mode, it loads data from the cache
    • Read more @ my blog h/ps:/
    /bit.ly/3mrna2i
    by @merowing_ 27
    

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28. by @merowing_ 28
    

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29. Need more power? Leverage unidirec3onal architecture/view state to implement 3me travel
    by @merowing_ 29
    

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30. Issue - Tes(ng Diffs
    Comparing objects is terrible.
    • Default Xcode results
    by @merowing_ 30
    

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31. Issue - Tes(ng Diffs
    Comparing objects is terrible.
    • Open Source Difference - Pure func.on Mirror based diffing
    by @merowing_ 31
    

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32. Issue - Boilerplate code
    and not thinking about Developer Experience
    by @merowing_ 32
    

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33. Sourcery
    • Sourcery is like a pre-processor
    • Sourcery(input: Swift) -> Either
    • Used in over 40 000 apps.
    • In massive code-bases like Airbnb, Bumble, etc.
    • Adds annota?on support to SwiA language
    • Allows fine-grained control over the genera?on
    • Sourcery can generate any code if you can describe the algorithm
    by @merowing_ 33
    

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34. by @merowing_ 34
    

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35. Example: Automa.c Se1ngs
    struct Calculation: AutomaticSettings {
    var text = ""
    var mode = Mode.linearRegression
    }
    // sourcery: injectFooter
    struct Smoothing {
    var dayPeriod = 7
    var algorithm = Algorithm.movingAverage
    struct Grouped {
    var level: Float = 1
    var prettyCool = true
    }
    var grouped: Grouped = .init()
    }
    by @merowing_ 35
    

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36. Example: A/B Tests
    struct ABTests {
    var meterLimit = Test(
    default: .control
    )
    var calendarReminder = Test(
    default: .control
    )
    ....
    }
    by @merowing_ 36
    

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37. Example: JS <-> Swi1 bridge
    // 1 case -> 1 command
    case nodesSetAutoFade(ids: [String], maxDistance: CGFloat)
    case nodesSetVisibility(showIds: [String]?, hideIds: [String]?)
    case materialSetProperties(
    id: String,
    material: String,
    properties: ARViewer.Model.MaterialProperties
    )
    // automatically bridges JS <-> Swift and provided as fully typed enum
    switch (command) {
    case let .materialSetProperties(id, materialName, properties):
    by @merowing_ 37
    

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38. But ... it's a dependency. I don't know if my
    team will want or can integrate it?
    by @merowing_ 38
    

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39. Sourcery Pro
    with Xcode Live templates
    by @merowing_ 39
    

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40. by @merowing_ 40
    

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41. by @merowing_ 41
    

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42. Sourcery Pro
    with Xcode Live templates
    by @merowing_ 42
    

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43. Issue - Tes(ng Mocks
    • Open Source Swi&yMocky - Sourcery based framework for
    powerful mocking DSL
    • Open Source Sourcery - AutoMockable template
    by @merowing_ 43
    

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44. Issue - Tes(ng Mocks
    • Sourcery Pro Live AST Templates
    by @merowing_ 44
    

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45. Issue - Long itera/on cycle
    by @merowing_ 45
    

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46. Issue - Long itera/on cycle
    by @merowing_ 46
    

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47. Issue - Long itera/on cycle
    First, we can split the project into many different modules.
    • Improves modular architecture design
    • Forces developers to think about public API and module boundaries
    • Each framework has its test suite that can run fast
    • Enables use of playgrounds or small projects
    • .dylib loading is no longer a significant concern, and we have staBc
    libs
    by @merowing_ 47
    

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48. Issue - Long itera/on cycle
    Open Source: KZPlayground
    • Both Swi* and Objec3ve-C
    • Custom DSL for exposing control variables (sliders, image
    pickers, trigger buEons).
    • It's easy to add the framework to exis3ng code-base
    • Works with Injec3onForXcode
    by @merowing_ 48
    

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49. by @merowing_ 49
    

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50. Not convinced yet?
    What if you only needed a maximum of two line change to hot-
    reloading your UIKit / AppKit / tvOS / Swi>UI project?
    UIKit/AppKit:
    // from
    let vc = MainViewController(...)
    // to
    let vc = Inject.ViewControllerHost(MainViewController(...))
    by @merowing_ 50
    

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51. by @merowing_ 51
    

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52. Not convinced yet?
    What if you only needed a maximum of two line change to hot-
    reloading your UIKit / AppKit / tvOS / Swi>UI project?
    Swi$UI:
    @ObservedObject private var iO = Inject.observer variable
    var body: some View {
    ...
    .enableInjection()
    }
    by @merowing_ 52
    

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53. by @merowing_ 53
    

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54. Issue - Long itera/on cycle
    What if you can't split up your project easily or it's s4ll too slow?
    • Open Source: Inject + Injec+onForXcode
    • Hot Reloading for Swi: and Objec+ve-C
    • No run+me involved, full Swi: support
    • Can be integrated as an SPM package
    by @merowing_ 54
    

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55. Summary
    • Crea&ng a good developer experience should be one of the main goals of your applica&on
    architecture design
    • Time invested into improving your team developer experience can yield huge ROI for your
    business
    • By enabling your developers to work on the features that maAer to the business
    • If a mythical 10x developer exists, it would be the person that makes ten team members more
    efficient.
    • Ask yourself if the problems you are facing are isolated or affect other devs?
    • Consider geHng Sourcery Pro to automate your workflows
    • Give Inject a try if you want to save hours of development :me per week
    by @merowing_ 55
    

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56. Ques%ons?
    by @merowing_ 56
    

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57. Contact
    Twi$er merowing_
    Github krzysztofzablocki
    Blog: h"ps:/
    /merowing.info
    by @merowing_ 57
    

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