Scala 3 slowed us down?
4 days ago
- #Migration
- #Performance
- #Scala
- The article discusses a performance issue encountered during a migration from Scala 2.13 to Scala 3.
- Initial migration steps were smooth with no immediate issues detected in testing environments.
- A mysterious slowdown occurred in production, leading to increased Kafka lag and reduced processing rates.
- Profiling revealed a significant performance degradation in a quicklens library call under Scala 3.
- Updating the problematic library resolved the performance issues, making Scala 3 performance comparable to Scala 2.13.
- The key takeaway is to benchmark performance-critical sections post-migration, especially when using meta-programming libraries.