Case Study: Zalando achieves 3.2x faster Scala compilation with Gradle Technologies

How Zalando Achieved 3.2X Faster Scala Compilation Times

Zalando, a major European e-commerce company, faced a significant challenge as compilation times for their Scala-based "tinbox" application backend had doubled in a single month, severely hampering developer productivity. Their use of type-intensive libraries led to long and unpredictable compile times, making it difficult to identify the root cause of the slowdown.

To address this, Zalando worked with Gradle's partner, Triplequote, and implemented their Hydra parallel Scala compiler. This solution was complemented by advanced diagnostic tooling that pinpointed a specific inefficiency in macro expansion. By optimizing this code and utilizing Hydra to parallelize the compilation process across multiple cores, Zalando achieved a 3.2x faster compilation speed, drastically improving both developer and continuous integration workflows.

Zalando