### Architecture
- [Doordash mobile architecture](https://doordash.engineering/2019/12/12/our-tech-stack-in-the-android-dasher-app/)
- [Evernote rewrite mobile app](https://evernote.com/blog/we-rebuilt-evernote-for-ios-in-swift/)
- [Scaling up an iOS app using modules](https://engineering.depop.com/scaling-up-an-ios-app-with-modularisation-8cd280d6b2b8)
### Offline Sync and Cache
- [Dropbox photo offline sync](https://dropbox.tech/mobile/building-carousel-part-i-how-we-made-our-networked-mobile-app-feel-fast-and-local)
- [Airbnb message sync](https://medium.com/airbnb-engineering/messaging-sync-scaling-mobile-messaging-at-airbnb-659142036f06)
- [Netflix download](https://www.youtube.com/watch?v=x1fF6_U9jdY)
- [Trello offline works](https://tech.trello.com/sync-architecture/)
- [Expedia API cache](https://medium.com/expedia-group-tech/how-apollo-android-client-cache-works-at-vrbo-73334d98af43)
- [LinkedIn Stories feature](https://engineering.linkedin.com/blog/2020/building-stories-on-ios)
### Chat system
- [Facebook Building Mobile-First Infrastructure](https://engineering.fb.com/2014/10/09/production-engineering/building-mobile-first-infrastructure-for-messenger/)
- [Instagram direct message](https://instagram-engineering.com/making-direct-messages-reliable-and-fast-a152bdfd697f)
- [Twitch native chat](https://blog.twitch.tv/en/2016/07/15/high-performing-native-chat-on-twitch-79c1492eca06/)
### Search effectively
- [Yelp Search part 1](https://engineeringblog.yelp.com/2018/05/android-search-perf-improvements-part-1.html)
- [Yelp Search part 2](https://engineeringblog.yelp.com/2018/05/android-search-perf-improvements-part-2.html)
- [Yelp Search part 3](https://engineeringblog.yelp.com/2018/06/android-search-perf-improvements-part-3.html)
### Networking
- [Lyft Decomposing network calls](https://eng.lyft.com/decomposing-network-calls-on-the-lyft-mobile-apps-c352de8e5e77)
- [Instagram background data prefetching](https://instagram-engineering.com/improving-performance-with-background-data-prefetching-b191acb39898)
- [Driver Profiles: How Uber Engineering Celebrates Drivers](https://eng.uber.com/driver-profiles/)
- [Best Practices for Mobile-Friendly APIs - Natasha Robot](https://www.natashatherobot.com/best-practices-mobile-friendly-apis/)
- [A Massive Guide to Building a RESTful API for Your Mobile App](https://savvyapps.com/blog/how-to-build-restful-api-mobile-app)
- [Real time data exchange using web sockets in iOS 13](https://www.donnywals.com/real-time-data-exchange-using-web-sockets-in-ios-13/)
### From Apple
- [Writing Energy Efficient Apps](https://apple.co/2EsDQ85)
### Interview
- [Grokking the Mobile System Design interview](https://medium.com/@goncharov.artemv/grokking-the-mobile-system-design-interview-6a06fa94491b)
- [Mobile System Design Interviews (iOS and Android)](https://blog.usejournal.com/mobile-system-design-interviews-ios-and-android-f5d360292c22)
- [iOS System Design Interview - Alex Bush, Course](https://iosinterviewguide.com/system-design-interview)
- [How I would solve the Facebook iOS App Design Interview](https://www.davidseek.com/fb/)