Case Study: Coursera reduces Scala compilation times with Gradle Hydra

How Coursera Reduced Scala Compilation Times By 125 Hours a Week

Coursera, a leading online education platform, faced a significant challenge with slow Scala compilation times in their large monorepo containing nearly 2 million lines of code. A full compilation took about 30 minutes, which hindered the productivity of their 60 backend developers and their CI infrastructure. To address this, they turned to a solution from vendor Gradle.

Gradle's solution, referred to as Hydra, was implemented with a setup time of only five minutes and required no code changes. The tool provided immediate and reliable compilation speedups and a dashboard for monitoring metrics. As a result, Coursera saved 125 hours of developer time per week and significantly reduced compilation times on their CI infrastructure, leading to a major boost in engineering productivity.

Coursera

David Guo

Dev Infrastructure Engineer