When Lambdas Can't Serialize: Building AST-Based Transformation Pipelines in Kotlin

As kumulant transitioned from in-process Kotlin code to cloud-deployed YAML configurations, lambdas became a fundamental blocker—functions cannot serialize over HTTP. By replacing closures with a polymorphic, serializable AST (Abstract Syntax Tree), the library now enables developers to define complex transformations in YAML while preserving type safety. This shift reveals a broader architectural truth: cloud-native systems require composable expressions, not embedded code.