Empowering iOS Developers Samuel Giddins Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 1 

Samuel Giddins Mobile Developer Experience @ Square Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 2 

Formerly: ‣ iOS Open Source ‣ RubyGems ‣ Bundler ‣ Realm ‣ CocoaPods Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 3 

What do all these all have in common? Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 4 

What do all these all have in common? Building tools for other developers Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 5 

Why build tools? ‣ Higher leverage ‣ Building things for those sitting around me ‣ Easier to do open source / share Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 6 

So, what about this topic has to do with iOS Developers? Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 7 

(Quick) Trip through history ‣ Pre-2.0 ‣ Only jailbreak apps ‣ A few years of small apps ‣ Lots of apps built by agencies / consultancies ‣ iOS 7 ‣ Everyone rewrote everything ‣ Apps got big ‣ Now ‣ Multinational companies base their business off of mobile apps Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 8 

The largest iOS apps are bigger than some small companies' entire codebases (across all engineering disciplines) Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 9 

Think ‣ Facebook ‣ Instagram ‣ Gmail ‣ Airbnb ‣ Uber ‣ Square Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 10 

Even the smallest apps have gotten bigger, as platform expectations have grown Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 11 

Before Now Nav bar & table view Rich collections Pixel-perfect PNGs Scalable designs CRUD APIs Instant syncing Multitasking Extensions Multiple input options State restoration Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 12 

I work on a massive app. Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 13 

I work on a massive app. We have 390+ source files. Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 14 

I work on a massive app. We have 390+ source files. We have 390+ modules. Some of which have hundreds of files. Then there are the tests. Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 15 

I work on a massive app 6 massive apps. Business reasons dictate we have multiple apps (and a couple of SDKs!) all built on a common platform. Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 16 

Built by ‣ Multiple engineering teams ‣ across a half dozen different offices ‣ spanning different organizations in the company ‣ each with their own product manager & designer Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 17 

90% of those teams are responsible for shipping features Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 18 

I’m in the 10%. I ship features to everyone else. Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 19 

Server engineers hit this scale a long long time ago, they had a solution called platform engineering Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 20 

Platform Engineering mix of devops stuff and writing frameworks Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 21 

Platform Engineering Took longer on mobile because getting to scale took longer Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 22 

All we need is what  gives us! 1 The i OS Community Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 23 

Then Now 1-3 people collaborating on a single app, in their free time four thousand person business making money primarily through their apps Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 24 

What can we provide? Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 25 

What can we provide? Look to what server folks did! ‣ Developer environment ‣ Write some tests ‣ CI / automated testing setup ‣ Automated deployment ‣ “Frameworks” ‣ Task automation ‣ Build systems ‣ IDEs Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 26 

The goal: allow engineers to focus on building product Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 27 

Make the path from product managers & designers to the built app be as easy as possible Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 28 

If you work on a small team, this may sound strange Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 29 

If you work on a small team, this may sound strange but think of all the small parts of your job you try to ignore Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 30 

‣ Updating to new Xcode versions ‣ Keeping the build passing ‣ Uploading builds to testflight / the appstore ‣ Investigating Xcode doing something silly ‣ Speeding up a slow build ‣ Updating network request / response code ‣ Protobufs! Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 31 

As you reach a certain team size, it makes sense to invest in expertise in those kinds of problems Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 32 

There’s something in here for anyone to learn (regardless of team size) Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 33 

For every complaint you see about something getting in the way see if you can invest in a permanant fix Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 34 

everyday frustrations of being a developer pile up Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 35 

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No matter how many engineers you have, these frustrations are real costs your team faces Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 37 

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Every time master is red, someone has to go and look at why Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 39 

hey, not to be a broken record, but i had to rebuild the same commit 27 times (no rebases, exact same SHA) to get a green build last night Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 40 

github.com/square/refinement Selective test execution Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 41 

I was on vacation ! for a bit and came back this week and noticed that my builds were super fast! Sometimes I'd see some builds take 30-45 minutes (where I'd typically modify things that only touch Retail) but have noticed them go down to about 5 minutes (except for ALL, but this went from 1h+ to about 30 minutes, with is still huge)! Just wanna say how awesome that is " , seeing the reduced build times have me nurse PRs with less time, and I presume freeing resources for other folks Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 42 

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Built for Scale Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 44 

This kind of migration takes a lot of effort, and requires building up lots of specialized knowledge. Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 45 

This kind of migration takes a lot of effort, and requires building up lots of specialized knowledge. Just like you wouldn’t ask a java server engineer to build up your table views, it’d be a mistake to have an iOS developer replace your build system Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 46 

Projects like this require a combination of ownership & expertise Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 47 

At Square, the Platform Engineering team is over 100 people for server Our MDX team is 5 for iOS and 5 for Android Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 48 

Investing in these areas allows us to scale A team of 50 total mobile engineers to over 150 1 app to half a dozen Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 49 

no matter the team size, investing in increased productivity & developer happiness is worth it Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 50 

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Samuel Giddins @segiddins Empowering iOS Developers – Samuel Giddins @ MobileConf Thailand 2019 52