Scott Berrevoets - Architecture & Infrastructure

The foundations of a mobile platform

Scott Berrevoets — Tue, 11 Aug 2026 00:00:00 -0700

In larger teams or companies, most people agree that the mobile platform is the shared infrastructure an app and its features are built upon. In earlier stages, that might simply mean "shared code and helper functions", but when the app and team start scaling, the platform deserves a lot more …

Managing code deprecations on iOS

Scott Berrevoets — Wed, 20 Aug 2025 00:00:00 -0700

A great manager I once worked with had been at Google for a while and poked fun at an aspect of its engineering culture: any given service was either deprecated or not yet ready for adoption. I spend a lot of my time working on mobile platform development and over …

Flywheel of tech debt

Scott Berrevoets — Wed, 02 Jul 2025 00:00:00 -0700

Tech debt is often compared to financial debt, in that you're borrowing development time now to pay it off with more development time later. When "later" comes around, the development time needed to fix the issues introduced earlier is too high so the new thing is also not built "correctly …

Art of the state

Scott Berrevoets — Mon, 02 Jun 2025 00:00:00 -0700

@State plays a prominent role in any SwiftUI app, and for good reason: app state is what ultimately drives the UI and how the user interacts with your app. This has always been true, but SwiftUI embraces this reality with specific APIs and a unidirectional data flow. UIKit-based apps or …

Shifting the testing culture: Code coverage

Scott Berrevoets — Wed, 20 Nov 2024 00:00:00 -0800

Note

This is the third post in a series on shifting our testing culture.

Motivation
Infrastructure
Code coverage

Most people will say that code coverage is a measure of how well-tested your code is. I prefer to say it's a measure of how untested a codebase is. Take this example …

Shifting the testing culture: Infrastructure

Scott Berrevoets — Tue, 19 Nov 2024 00:00:00 -0800

Note

This is the second post in a series on shifting our testing culture.

Motivation
Infrastructure
Code coverage

This second article goes a bit deeper into the testing infrastructure we built over the years to optimize the ergonomics and developer experience as much as possible.

Our initial test suites only …

Migration strategies in large codebases

Scott Berrevoets — Tue, 15 Nov 2022 00:00:00 -0800

Code migrations are a fact of life for large codebases. New technologies pop up, platforms see improvements, and programming languages get new features you might want to adopt. Not performing these migrations and keeping up with the times is simply not an option in most cases. While some migrations are …

Third-party libraries are no party at all

Scott Berrevoets — Fri, 15 Jul 2022 00:00:00 -0700

What better way to end the week than with a hot take?

In my 8 years at Lyft, product managers or engineers have often wanted to add third-party libraries to one of our apps. Sometimes it’s necessary to integrate with a specific vendor (like PayPal), sometimes it’s to …

iOS Architecture at Lyft

Scott Berrevoets — Thu, 14 Oct 2021 00:00:00 -0700

June 30, 2014 was my first day at Lyft as the first iOS hire on the ~3 person team. The app was written in Objective-C, and the architecture was a 5000-line nested switch statement.

Since then, the team has grown to about 70 people and the codebase to 1.5M …