Uber automates migration of 75,000 JUnit 4 test classes to JUnit 5

Uber engineers automated the migration of over 75,000 JUnit 4 test classes to JUnit 5.

Published 11sem1 sourceNotableupdated 11sem

≈ 19sSpeed

The fact

This large-scale transition reduces technical debt and modernizes the testing infrastructure.

Automation enabled the migration without manual intervention on each class.

Explore this topic

Cross-sources — 1 source

Auto-synthesis from 1 media source · identified on April 27, 2026