Kyma Serverless Functions — When to Use & How to Build

Lesson 2.3 — Kyma Serverless Functions Table of Contents 1. Functions vs Microservices: Decision Framework 2. Function CRD 3. Binding BTP Services to Functions 4. Event-Triggered Functions 5. Practical Patterns Top 5 Pitfalls What to Learn Next Summary: Kyma Serverless Functions provide a lightweight, event-driven compute model for simple tasks — webhook handlers, data transformations, event processors — without the overhead of building Docker images and Helm charts. This lesson covers when to use functions vs microservices, the Function CRD, runtime environments, BTP service binding, and practical patterns. 1. Functions vs Microservices: Decision Framework Criteria Kyma Function Java Microservice Complexity Simple logic (< 500 LOC) Complex business logic Language Node.js, Python Java, Node.js, Go, any Startup time ~1-3s (cold start) ~15-60s (Spring Boot) Dependencies npm/pip packages only Full Maven/Gradle ecosystem Container control None (managed) Full Dockerfile control Scaling A