In the last few years, Lyft has invested heavily into the observability of our apps as we've scaled. At first we mostly treated the networking stack as a black box, hoping that the system would do a best effort to execute network requests and that influencing that was mostly out of our hands.
However, over time we discovered a lot more about how and when our network requests were failing, we developed ways to instrument the health of our apps in real time over billions of API requests a day, even triggering alarms when performance regressed. We also discovered how to tune the networking layer to perform best with various usage patterns for our different apps.
Ultimately, this resulted in us creating our own open source cross-platform mobile networking library that has given us unprecedented visibility and control into the performance of our apps at scale. You can find out more about it here:
https://envoymobile.io