5 ms·

The evolution of Facebook’s iOS app architecture

74 points by soheilpro 4y ago

fingerlocks 4y ago
It’s really hard for me to read this entire post without a nagging dismissive thought in the back of my mind: “They did all of this for a CRUD app?!” I’ve worked on some huge code bases for some very complicated iOS apps, but nothing that comes close to amount of engineering involved here. I wish they went into more depth of what exactly motivated these engineering design decisions so I could understand the problem space. It reads like they had some threading issues in core data, and solved it by completely rearchitecting a new UI framework? Really? Apple seems capable of shipping products using the existing public SDK for the last 15 years, so whats fundamentally different here? I can’t help but wonder if this was all the result of massive over-engineering.
- deleted 4y ago
  [deleted]
- pixel_tracing 4y ago
  Yea I lol’d hard, it’s like some great massive achievement and then you go work at Google and Apple and realize there’s actual systems engineering under the hood (kernel, process scheduling, daemons, etc.)
- saurik 4y ago
  > Apple seems capable of shipping products using the existing public SDK for the last 15 years... ? Apple definitely isn't using "the existing public SDK" to build their apps, and absolutely has not been doing so for 15 years: they didn't even adopt their own UIViewController abstractions until like iOS 4 or so, and usage of classes like UIScroller (not UIScrollView) UITable (not UITableView) and UIDocumentView (not UIWebView) continued for a long time while they tried to make the public versions of the API acceptable enough for real apps.
  - fingerlocks 4y ago
    Of course I was being flippant, and I think you know that.
    - sokoloff 4y ago
      That did not at all come through to this reader.
- School-Cotton 4y ago
  FBiOS is almost certainly the biggest and most complicated mobile app in the world (edit: perhaps outside of Asia, whose mobile app landscape I’m not familiar with). There is a truly dizzying amount of features, different types of news feed stories with different behavior, etc. Everything described in this article (or at least the parts I have direct knowledge of, which is a sizable chunk of it) was essential to force the thing to continue working at all. It’s not over-engineering, it’s over-producting: Facebook (err… sorry, “Meta”) is politically and culturally incapable of cutting bloat, making engineering solutions like these necessary.
seanhunter 4y ago
Work expands to fill the time of the team allocated to it. This whole article reminds me of the tech blog from Uber[1] proudly describing how they had made their own geofencing system that was worse than what comes out of the box with postgis[2]. [1] https://www.uber.com/en-GB/blog/go-geofence-highest-query-per-second-service/ https://www.uber.com/en-GB/blog/go-geofence-highest-query-pe... [2] https://www.cybertec-postgresql.com/en/beating-uber-with-a-postgresql-prototype/ https://www.cybertec-postgresql.com/en/beating-uber-with-a-p...
lawgimenez 4y ago
At some point I thought there was React Native in their iOS app.
- School-Cotton 4y ago
  There was (IIRC the Marketplace tab was all RN) and I suspect there still is.
  - cpeterso 4y ago
    Yes. Here’s a 2017 Facebook post about using React Native in Marketplace: https://reactnative.dev/blog/2017/08/07/react-native-performance-in-marketplace https://reactnative.dev/blog/2017/08/07/react-native-perform...

74 points by soheilpro 4y ago

It’s really hard for me to read this entire post without a nagging dismissive thought in the back of my mind: “They did all of this for a CRUD app?!” I’ve worked on some huge code bases for some very complicated iOS apps, but nothing that comes close to amount of engineering involved here. I wish they went into more depth of what exactly motivated these engineering design decisions so I could understand the problem space. It reads like they had some threading issues in core data, and solved it by completely rearchitecting a new UI framework? Really? Apple seems capable of shipping products using the existing public SDK for the last 15 years, so whats fundamentally different here? I can’t help but wonder if this was all the result of massive over-engineering.

deleted 4y ago
[deleted]
pixel_tracing 4y ago
Yea I lol’d hard, it’s like some great massive achievement and then you go work at Google and Apple and realize there’s actual systems engineering under the hood (kernel, process scheduling, daemons, etc.)
saurik 4y ago
> Apple seems capable of shipping products using the existing public SDK for the last 15 years... ? Apple definitely isn't using "the existing public SDK" to build their apps, and absolutely has not been doing so for 15 years: they didn't even adopt their own UIViewController abstractions until like iOS 4 or so, and usage of classes like UIScroller (not UIScrollView) UITable (not UITableView) and UIDocumentView (not UIWebView) continued for a long time while they tried to make the public versions of the API acceptable enough for real apps.
- fingerlocks 4y ago
  Of course I was being flippant, and I think you know that.
  - sokoloff 4y ago
    That did not at all come through to this reader.
School-Cotton 4y ago
FBiOS is almost certainly the biggest and most complicated mobile app in the world (edit: perhaps outside of Asia, whose mobile app landscape I’m not familiar with). There is a truly dizzying amount of features, different types of news feed stories with different behavior, etc. Everything described in this article (or at least the parts I have direct knowledge of, which is a sizable chunk of it) was essential to force the thing to continue working at all. It’s not over-engineering, it’s over-producting: Facebook (err… sorry, “Meta”) is politically and culturally incapable of cutting bloat, making engineering solutions like these necessary.

seanhunter 4y ago

Work expands to fill the time of the team allocated to it. This whole article reminds me of the tech blog from Uber[1] proudly describing how they had made their own geofencing system that was worse than what comes out of the box with postgis[2]. [1] https://www.uber.com/en-GB/blog/go-geofence-highest-query-per-second-service/ https://www.uber.com/en-GB/blog/go-geofence-highest-query-pe... [2] https://www.cybertec-postgresql.com/en/beating-uber-with-a-postgresql-prototype/ https://www.cybertec-postgresql.com/en/beating-uber-with-a-p...

lawgimenez 4y ago

At some point I thought there was React Native in their iOS app.

School-Cotton 4y ago
There was (IIRC the Marketplace tab was all RN) and I suspect there still is.
- cpeterso 4y ago
  Yes. Here’s a 2017 Facebook post about using React Native in Marketplace: https://reactnative.dev/blog/2017/08/07/react-native-performance-in-marketplace https://reactnative.dev/blog/2017/08/07/react-native-perform...