SoFi Innovation & Technology Culture

What’s your rule for fast, safe releases — and what KPI proves it works?

Code coverage is a single most important metric for assessing code health. It is a measure of how well our code has been covered with unit tests. Mobile repo has over 150 developers, and we merge over 25 changes each day. Unit tests provide the first level of defense and are a primary contributor to our stable, safe releases. Even though our code now has over 2 million lines of dart code, we have been shipping consistently to app stores every week for the past two years.

Which standard or metric defines “quality” in your stack?

Crash-free sessions: Crashes happen on mobile apps when the app gets into an unexpected state and it cannot provide accurate information for the member. The app closes suddenly. We track this metric pretty diligently, and it has been stellar in our Flutter app. Over the past three months, we have had 99.99 percent and 99.98 percent crash-free sessions on iOS and Android respectively, even though our app gets more than 1 million daily active users.

Name one recent AI/automation shipped and its impact on the team or business.

The mobile team has adopted a newer testing framework, using Mocktail over Mockito to reduce overhead of mock files. Conversion from Mockito to Mocktail is straightforward but tedious, so we create a comprehensive AI skill/Mockito-to-Mocktail that can take in a single file or multiple files and convert them correctly. 

We iterated on this skill with many examples and edge cases, and now we have 98 percent percent confidence that any given test file can easily be converted. This skill has helped the team reduce our tech debt and increase code quality.