diff --git a/CLAUDE.md b/CLAUDE.md
new file mode 100644
index 00000000..169bfe7e
--- /dev/null
+++ b/CLAUDE.md
@@ -0,0 +1,99 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Overview
+
+This is a multi-language, multi-sample repository of extension and application samples for [SAP BTP, Kyma Runtime](https://kyma-project.io/). Each top-level directory is an independent sample — there is no monorepo build system tying them together. Samples target deployment on Kubernetes (Kyma) via Docker containers.
+
+## Repository Structure
+
+Each sample is self-contained with its own:
+- `README.md` — setup and deployment instructions
+- `Makefile` — build, image, and deploy targets
+- `Dockerfile` (or buildpack config) — container build
+- Kubernetes manifests (in a `k8s/` subdirectory) or Helm charts
+
+Shared resources:
+- `prerequisites/README.md` — all required tooling by category
+- `helm-charts/` — reusable Helm charts
+- `workspaces/` — VS Code workspace files per sample
+- `assets/` — shared images/diagrams
+- `.github/workflows/` — CI workflows per sample
+
+## Build Commands
+
+### Root-level (Java samples only)
+```bash
+make build-java-projects   # builds sample-extension-java, sample-event-trigger-java, cloudsdk-client-cert-auth
+```
+
+### Per-sample (run from sample directory)
+Most samples follow this Makefile pattern:
+```bash
+make build          # compile/build the application
+make build-image    # build Docker image
+make push-image     # push to registry (requires DOCKER_PUSH_REPOSITORY etc.)
+make all            # clean + build + build-image + push-image
+```
+
+**Java (Gradle):**
+```bash
+./gradlew clean build
+./gradlew -Pversion=<version> -Pname=<app> clean build
+```
+
+**Go:**
+```bash
+go build ./...
+go test ./... -count=1
+```
+
+**.NET:**
+```bash
+dotnet build
+dotnet test
+```
+
+**Node.js/CAP:**
+```bash
+npm install
+npm run build   # or npm start
+cds build       # for CAP projects
+```
+
+## CI/CD
+
+Workflows in `.github/workflows/` follow a naming convention: `build-docker-<sample-name>.yml`, `build-and-publish-<sample-name>.yml`, `deploy-<sample-name>.yml`. Each workflow is independent and scoped to one sample. GitHub Actions uses JDK 17 (adopt distribution) for Java samples.
+
+## Key Technologies by Sample Category
+
+| Category | Samples | Stack |
+|----------|---------|-------|
+| Java microservices | `sample-extension-java`, `sample-event-trigger-java` | Spring Boot 3, Gradle, JDK 17 |
+| Go microservices | `orders-service`, `api-postgresql-go`, `app-auth-proxy` | Go 1.21, PostgreSQL/MSSQL |
+| .NET | `sample-extension-dotnet`, `sample-extension-dotnet-minimalapi` | ASP.NET Core, .NET 6+ |
+| Node.js functions | `s4hana-materialstock-function`, serverless functions | Node.js, SAP Cloud SDK |
+| Frontend | `frontend-react-mssql`, `frontend-ui5-postgresql` | React, SAPUI5 |
+| CAP | `from-zero-to-cap-on-kyma`, `cap-multitenancy-sample` | `@sap/cds-dk`, Node.js |
+| Mocks | `commerce-mock`, `c4c-mock`, `marketing-mock` | Node.js/TypeScript |
+| Auth | `user-propagation`, `app-auth-proxy` | XSUAA, OIDC, Go |
+| Advanced | `grpc-python`, `custom-component-dapr`, `sample-ldap` | Python, Dapr, LDAP |
+
+## Contributing
+
+- Propose changes via a GitHub issue first.
+- Squash multiple commits into one before submitting a PR.
+- Commit messages should reference issues: `Fixes https://github.com/SAP-samples/kyma-runtime-extension-samples/issues/<N>` (no colon after "Fixes").
+- DCO acceptance is required via CLA assistant on first PR.
+- Follow the coding standards of the language used in each sample.
+
+## Deployment Pattern
+
+All samples deploy to Kyma/Kubernetes. The typical workflow:
+1. Build the app (`make build`)
+2. Build and push a Docker image (`make build-image push-image`)
+3. Apply Kubernetes manifests (`kubectl apply -f k8s/`) or install Helm chart
+4. Configure SAP BTP service bindings as Kubernetes secrets
+
+Each sample's `README.md` documents the specific deployment steps and required environment variables/secrets.
diff --git a/sample-extension-java/Makefile b/sample-extension-java/Makefile
index 0736e37e..1637dd26 100644
--- a/sample-extension-java/Makefile
+++ b/sample-extension-java/Makefile
@@ -1,4 +1,4 @@
-RELEASE?=0.0.24
+RELEASE?=0.0.25
 APP?=sample-extension-java
 DOCKER_ACCOUNT?=gauravsap
 CONTAINER_IMAGE?=${DOCKER_ACCOUNT}/${APP}:${RELEASE}
@@ -16,7 +16,7 @@ build:
 build-image-using-pack: clean build
 	pack build $(APP) --tag $(CONTAINER_IMAGE) \
 		--path . \
-		--builder paketobuildpacks/builder:tiny \
+		--builder paketobuildpacks/builder-jammy-tiny \
 		--env BP_JVM_VERSION=17
 
 build-image-using-docker: clean build