Worked on the typelevel/otel4s repository to optimize performance and ensure correctness in hashCode semantics across core data structures. Introduced a lazy evaluation strategy in Scala, leveraging JVM features to compute and cache hashCode results, thereby reducing redundant calculations and improving efficiency. After benchmarking and further analysis, reverted the lazy val optimization to restore direct hashCode() invocation, maintaining correctness across all modules and SDK components. This work involved careful code refactoring and performance tuning, balancing optimization with the need for reliable behavior. Demonstrated a methodical approach to software engineering, focusing on both performance gains and the integrity of core functionality.