BFFs For Swift

Many modern apps need to make 10s or even 100s or network calls just to populate the home screen. And they'll likely be calling multiple different APIs, all requiring different authentication methods, JSON parsing and aggregation. Not only does this increase battery drain and frustration for users on slow and unreliable networks, it places a huge burden on the developer that isn't easy to update or iterate on quickly.

In this talk we'll look at the Backend for Frontend pattern and see how we can leverage Swift in both our iOS applications and server applications to share code and make development faster. We'll show clear examples of how BFFs can dramatically simplify your networking code and how a BFF in Swift can help you develop iOS applications quicker by reducing context switching and being able to share code.

Transcript

1. BFFs For Swift
   Tim Condon
   @0xTim
   

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2. BFFs For Swift
   @0xTim
   The Backend Problem
   General Purpose API
   Web Client
   

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3. BFFs For Swift
   @0xTim
   The Backend Problem
   General Purpose API
   Web Client
   iOS App Android App
   

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4. BFFs For Swift
   @0xTim
   The Backend Problem
   General Purpose API
   Web Client
   iOS App Android App
   Mobile Web
   Client
   TV Client
   

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5. BFFs For Swift
   @0xTim
   The Backend Problem
   General Purpose API
   Web Client
   iOS App Android App
   Mobile Web
   Client
   3rd Party
   Service
   3rd Party
   Service
   TV Client
   

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6. View Slide

7. BFFs For Swift
   @0xTim
   The Backend Problem
   iOS App
   Monolith
   

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8. BFFs For Swift
   @0xTim
   The Backend Problem
   iOS App
   Monolith
   Microservice
   

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9. BFFs For Swift
   @0xTim
   The Backend Problem
   iOS App
   Microservice
   Microservice
   Microservice
   Microservice Microservice
   

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10. BFFs For Swift
    @0xTim
    The Backend Problem
    iOS App
    Microservice
    Google API
    AWS API
    Microservice
    Microservice
    Microservice Microservice
    

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11. View Slide

12. BFFs For Swift
    @0xTim
    The Homescreen Problem
    Events
    Location
    Schedule
    Speakers
    

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13. BFFs For Swift
    @0xTim
    The Homescreen Problem
    Events
    Location
    Schedule
    Speakers
    GET /api/events/coming-up
    {
    "page": {
    "totalPages": 11,
    "nextPage": "/api/events/coming-up?page=2&count=100"
    },
    "events": [
    {
    "id": "5212187e-e431-46eb-aebd-be0fccd9a2fb",
    "name": "dotSwift",
    "start": "2020-02-03T09:30:00+01:00",
    "end": "2020-02-03T18:30:00+01:00",
    "speakers": [
    "e6adf697-4c6b-48e8-b5c0-27a0b305ce09",
    ...
    "fb9989a4-97b3-472e-93b5-efaf8d207dfe"
    ],
    "emcee": "9ef5e988-18cd-438b-a61b-7334986c67ec",
    "location": {
    "latitude": 48.878765,
    "longitude": 2.330944,
    "id": "a1a02cd0-2a94-425d-bd04-c2d054ce254a"
    }
    }
    ],
    ...
    }
    

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14. BFFs For Swift
    @0xTim
    The Homescreen Problem
    Events
    Location
    Schedule
    Speakers
    GET /api/locations/a1a02cd0-2a94-425d-bd04-c2d054ce254a
    {
    "latitude": 48.878765,
    "longitude" 2.330944,
    "name": "Théâtre de Paris",
    "address": "15 Rue Blanche, 75009 Paris",
    "nearest-stations": [
    {
    "line": "Green 12",
    "name": "Trinité"
    },
    ...
    ]
    ...
    }
    

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15. BFFs For Swift
    @0xTim
    The Homescreen Problem
    Events
    Location
    Schedule
    Speakers
    GET /api/events/5212187e-e431-46eb-aebd-be0fccd9a2fb/schedule
    {
    "talks": [
    ...
    {
    "title": "BFFs For Swift",
    "speaker": "e6adf697-4c6b-48e8-b5c0-27a0b305ce09",
    "start-time": "2020-02-03T14:30:00+01:00",
    "end-time": "2020-02-03T14:50:00+01:00",
    "room": "f5536b5a-223b-4a1a-b050-836bd4e924fa"
    },
    {
    "title": "Property Wrappers or How Swift decided to
    become Java",
    "speaker": "fb9989a4-97b3-472e-93b5-efaf8d207dfe",
    "start-time": "2020-02-03T15:30:00+01:00",
    "end-time": "2020-02-03T15:50:00+01:00",
    "room": "9a1a7f2d-230e-40e0-8757-dc80ec4aa25d"
    },
    ...
    ],
    "breaks": {
    ...
    }
    }
    

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16. BFFs For Swift
    @0xTim
    The Homescreen Problem
    Events
    Location
    Schedule
    Speakers
    GET /api/speakers/e6adf697-4c6b-48e8-b5c0-27a0b305ce09/
    {
    "name": "Tim Condon",
    "profile-image": "https://s3-eu-central-1.amazonaws.com/
    static-dotconferences-com/speakers_images/tim-condon.png",
    "talk": "c3d5735e-f8a3-4ca4-94c7-802c8f4306db",
    "bio": "Tim is the server-side Swift team lead at
    raywenderlich.com and has written the unofficial-official book
    on Vapor with the founders of the framework. He founded Broken
    Hands and delivers talks and workshops on Vapor and server-side
    Swift around the world. He also co-organises the
    ServerSide.swift conference.",
    "github": "0xTim",
    "twitter": "0xTim"
    }
    

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17. BFFs For Swift
    @0xTim
    The Homescreen Problem
    Events
    Location
    Schedule
    Speakers
    GET /api/events/coming-up
    {
    "page": {
    "totalPages": 11,
    "nextPage": "/api/events/coming-up?page=2&count=10"
    },
    "events": [
    {
    "name": "dotSwift",
    "date": "2020-02-03T00:00:00+01:00",
    "location": {
    "name": "Théâtre de Paris",
    "address": "15 Rue Blanche, 75009 Paris",
    },
    "onNow": {
    "title": "BFFs For Swift",
    "startTime": "2020-02-03T14:30:00+01:00",
    "endTime": "2020-02-03T14:50:00+01:00",
    "speakerName": "Tim Condon"
    }
    }
    ],
    ...
    }
    

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18. BFFs For Swift
    @0xTim
    The Homescreen Problem
    Events
    Location
    Schedule
    Speakers
    

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19. BFFs For Swift
    @0xTim
    The Homescreen Problem
    Events
    Location
    Schedule
    Speakers
    iOS Team
    API Team
    

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20. View Slide

21. BFFs For Swift
    @0xTim
    The Homescreen Problem
    Events
    Location
    Schedule
    Speakers
    

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22. View Slide

23. Backend For Frontend
    

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24. BFFs For Swift
    @0xTim
    BFFs To The Rescue
    iOS App
    General
    Purpose API
    Weather API
    AWS
    Microservice
    Microservice
    

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25. BFFs For Swift
    @0xTim
    BFF
    BFFs To The Rescue
    iOS App
    General
    Purpose API
    Weather API
    AWS
    Microservice
    Microservice
    

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26. BFFs For Swift
    @0xTim
    BFFs To The Rescue
    BFF
    iOS App
    GET /api/events/coming-up
    {
    "page": {
    "totalPages": 11,
    "nextPage": "/api/events/coming-up?page=2&count=10"
    },
    "events": [
    {
    "name": "dotSwift",
    "date": "2020-02-03T00:00:00+01:00",
    "location": {
    "name": "Théâtre de Paris",
    "address": "15 Rue Blanche, 75009 Paris",
    },
    "onNow": {
    "title": "BFFs For Swift",
    "startTime": "2020-02-03T14:30:00+01:00",
    "endTime": "2020-02-03T14:50:00+01:00",
    "speakerName": "Tim Condon"
    }
    }
    ],
    ...
    }
    

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27. BFFs For Swift
    @0xTim
    BFF Ownership
    iOS App
    AWS API
    iOS BFF
    Microservice
    Microservice
    Microservice
    Android BFF
    Web BFF
    Android App
    Website Client
    

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28. BFFs For Swift
    @0xTim
    BFF Ownership
    iOS App
    AWS API
    iOS BFF
    Microservice
    Microservice
    Microservice
    Android BFF
    Web BFF
    Android App
    Website Client
    API Team
    iOS Team
    Android Team
    Web Team
    

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29. – Sam Newman, Thoughtworks
    “The BFF is tightly coupled to a specific user
    experience, and will typically be maintained by the
    same team as the user interface, thereby making it
    easier to define and adapt the API as the UI requires,
    while also simplifying process of lining up release of
    both the client and server components.”
    

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30. BFFs For Swift
    @0xTim
    BFF Examples
    

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31. BFFs in Swift
    

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32. BFFs For Swift
    @0xTim
    Swift on the Server
    

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33. BFFs For Swift
    @0xTim
    Is it ready for production?
    

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34. View Slide

35. BFFs For Swift
    @0xTim
    Swift in BFFs
    

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36. BFFs For Swift
    @0xTim
    Sharing Code
    

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37. BFFs For Swift
    @0xTim
    Sharing Code
    BFF Models Package
    BFF
    

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38. BFFs For Swift
    @0xTim
    GET /api/events/coming-up
    {
    "page": {
    "totalPages": 11,
    "nextPage": "/api/events/coming-up?page=2&count=10"
    },
    "events": [
    {
    "name": "dotSwift",
    "date": "2020-02-03T00:00:00+01:00",
    "location": {
    "name": "Théâtre de Paris",
    "address": "15 Rue Blanche, 75009 Paris",
    },
    "on-now": {
    “title": "BFFs For Swift",
    "startTime": "2020-02-03T14:30:00+01:00",
    "endTime": "2020-02-03T14:50:00+01:00",
    "speakerName": "Tim Condon"
    }
    }
    ],
    ...
    }
    struct ComingUpResponse: Codable {
    let page: PaginationInformation
    let events: [ComingUpEvent]
    }
    struct PaginationInformation: Codable {
    let totalPages: Int
    let nextPage: URL
    }
    Sharing Code
    

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39. BFFs For Swift
    @0xTim
    Sharing Code
    GET /api/events/coming-up
    {
    "page": {
    "totalPages": 11,
    "nextPage": "/api/events/coming-up?page=2&count=10"
    },
    "events": [
    {
    "name": "dotSwift",
    "date": "2020-02-03T00:00:00+01:00",
    "location": {
    "name": "Théâtre de Paris",
    "address": "15 Rue Blanche, 75009 Paris",
    },
    "on-now": {
    “title": "BFFs For Swift",
    "startTime": "2020-02-03T14:30:00+01:00",
    "endTime": "2020-02-03T14:50:00+01:00",
    "speakerName": "Tim Condon"
    }
    }
    ],
    ...
    }
    struct ComingUpEvent: Codable {
    let name: String
    let date: Date
    let location: ComingUpLocation
    let onNowInfo: ComingUpOnNowInfo
    }
    struct ComingUpLocation: Codable {
    let name: String
    let address: String
    }
    struct ComingUpOnNowInfo: Codable {
    let title: String
    let startTime: Date
    let endTime: Date
    let speakerName: String
    }
    

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40. BFFs For Swift
    

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41. Thank you!
    @0xTim
    

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