diff --git a/.github/workflows/backend-sonarqube-analysis.yml b/.github/workflows/backend-sonarqube-analysis.yml
index 3375873c..ef1fcb99 100644
--- a/.github/workflows/backend-sonarqube-analysis.yml
+++ b/.github/workflows/backend-sonarqube-analysis.yml
@@ -40,7 +40,7 @@ jobs:
           cache: maven
 
       - name: mvn package
-        run: mvn -B verify --file backend/pom.xml
+        run: mvn -B clean verify --file backend/pom.xml
 
       - name: Cache SonarQube packages
         uses: actions/cache@v4
diff --git a/.github/workflows/backend.yml b/.github/workflows/backend.yml
index d807d882..51a6a2fa 100644
--- a/.github/workflows/backend.yml
+++ b/.github/workflows/backend.yml
@@ -42,7 +42,7 @@ jobs:
 
       # only build relevant service
       - name: mvn package
-        run: mvn -B package --file backend/${{ matrix.service.directory }}/pom.xml
+        run: mvn -B clean package --file backend/${{ matrix.service.directory }}/pom.xml
 
       - name: Extract metadata (tags, labels) for Docker
         id: meta
diff --git a/backend/app.hopps.org/src/main/java/app/hopps/org/jpa/TreeSearchBommel.java b/backend/app.hopps.org/src/main/java/app/hopps/org/jpa/TreeSearchBommel.java
index b4fedf59..f5013dcf 100644
--- a/backend/app.hopps.org/src/main/java/app/hopps/org/jpa/TreeSearchBommel.java
+++ b/backend/app.hopps.org/src/main/java/app/hopps/org/jpa/TreeSearchBommel.java
@@ -1,12 +1,15 @@
 package app.hopps.org.jpa;
 
+import com.fasterxml.jackson.annotation.JsonIgnore;
+
 import java.util.Arrays;
 import java.util.List;
 
 public record TreeSearchBommel(
         Bommel bommel,
-        boolean cycleMark,
+        @JsonIgnore boolean cycleMark,
         List<Long> cyclePath) {
+
     public TreeSearchBommel(Bommel bommel, Boolean cycleMark, String cyclePath) {
         this(bommel, cycleMark != null && cycleMark, parseCyclePath(cyclePath));
     }
diff --git a/backend/app.hopps.org/src/main/resources/application.properties b/backend/app.hopps.org/src/main/resources/application.properties
index 217e4030..c8d6c920 100644
--- a/backend/app.hopps.org/src/main/resources/application.properties
+++ b/backend/app.hopps.org/src/main/resources/application.properties
@@ -10,7 +10,8 @@ quarkus.banner.path=banner.txt
 quarkus.flyway.migrate-at-start=true
 quarkus.flyway.baseline-on-migrate=true
 quarkus.flyway.clean-at-start=false
-#
+%test.quarkus.flyway.locations=db/migration,db/testdata
+%dev.quarkus.flyway.locations=db/migration,db/testdata
 ########################################
 # Keycloak/auth
 ########################################
diff --git a/backend/app.hopps.org/src/main/resources/db/testdata/V2.0.0__test_data.sql b/backend/app.hopps.org/src/main/resources/db/testdata/V2.0.0__test_data.sql
new file mode 100644
index 00000000..2e9e4826
--- /dev/null
+++ b/backend/app.hopps.org/src/main/resources/db/testdata/V2.0.0__test_data.sql
@@ -0,0 +1,104 @@
+insert into Organization (type, id, slug, name, website, plz, city, street, number)
+values
+(0, 2, 'gruenes-herz-ev', 'Grünes Herz e.V.', 'https://gruenes-herz.de/', '27324', 'Schweringen', 'Am Lennestein', '110'),
+(0, 3, 'kaeltekrieger', 'Eishockeyclub Kältekrieger e.V.', 'https://kaeltekrieger.de/', '89129', 'Langenau', 'August-Brust-Straße', '78'),
+(0, 4, 'buehnefrei-ev', 'Theatervereine Bühnefrei e.V.', 'https://bühnefrei.de/', '33397', 'Rietberg', 'Dechant-Karthaus-Straße', '172');
+
+insert into member
+(id, email, firstName, lastName)
+values
+-- gruenes-herz-ev
+(2, 'emanuel_urban@domain.none', 'Emanuel', 'Urban'),
+(3, 'hartlieb-reuter@xyz.none', 'Hartlieb', 'Reuter'),
+(4, 'elgard-nicklas@trashmail.none', 'Elgard', 'Nicklas'),
+(5, 'gerald.geiger@company.none', 'Gerald', 'Geiger'),
+(6, 'jannick.1923@net-mail.none', 'Jannick', 'Cao'),
+(7, 'constance.wendling@justmail.none', 'Constance', 'Wendling'),
+(8, 'florenz-huefner@spam-mail.none', 'Florenz', 'Häfner'),
+-- kaeltekrieger
+(9, 'h1978@company.none', 'Herlind', 'Kutscher'),
+(10, 'annekathrinfeldhoff@inter-mail.none', 'Annekathrin', 'Feldhof'),
+(11, 'rosegunde-19@anymail.none', 'Rosegunde', 'Wilhelmy'),
+(12, 'eckhardweirich@spam-mail.none', 'Eckhard', 'Weirich'),
+(13, 'g_2011@inter-mail.none', 'Godo', 'Beckers'),
+(14, 'klothilde1916@net-mail.none', 'Klothilde', 'Püppel'),
+-- buehnefrei-ev
+(15, 'samantha1284@net-mail.none', 'Samantha', 'Adomeit'),
+(16, 'm-linner@private.none', 'Margund', 'Linner'),
+(17, 'b-bork@mymail.none', 'Birgit', 'Bork'),
+(18, 'gkalb@quickmail.none', 'Gunther', 'Kalb'),
+(19, 'b-schlicker@trashmail.none', 'Burckhard', 'Schlicker'),
+(20, 'alix1980@validmail.none', 'Alix', 'Raff');
+
+insert into Member_Verein (member_id, organizations_id)
+values
+-- gruenes-herz-ev
+(2, 2),
+(3, 2),
+(4, 2),
+(5, 2),
+(6, 2),
+(7, 2),
+(8, 2),
+-- kaeltekrieger
+(9, 3),
+(10, 3),
+(11, 3),
+(12, 3),
+(13, 3),
+(14, 3),
+-- buehnefrei-ev
+(15, 4),
+(16, 4),
+(17, 4),
+(18, 4),
+(19, 4),
+(20, 4);
+
+insert into Bommel (id, parent_id, name, emoji, responsibleMember_id)
+values
+-- gruenes-herz-ev (id=2)
+(2, null, 'Grünes Herz e.V.', null, null),
+(3, 2, 'Fundraising & Spenden', null, null),
+(4, 2, 'Bildungs-Projekte', null, null),
+(5, 2, 'Naturschutz-Projekte', null, null),
+(6, 4, 'Schulvorträge', null, null),
+(7, 4, 'Online Seminare', null, null),
+(8, 6, 'Vortrag 1', null, null),
+(9, 6, 'Vortrag 2', null, null),
+(10, 5, 'Schutz eines Feuchte-Gebietes', null, null),
+-- kaeltekrieger (id=3)
+(11, null, 'Kältekrieger e.V.', null, null),
+(12, 11, 'Verkauf', null, null),
+(13, 11, 'Öffentlicher Lauf', null, null),
+(14, 11, 'Mannschaften', null, null),
+(15, 11, 'Stadion', null, null),
+(16, 12, 'Kiosk', null, null),
+(17, 12, 'Shop', null, null),
+(18, 14, '1. Liga', null, null),
+(19, 14, '2. Liga', null, null),
+(20, 14, '3. Liga', null, null),
+(21, 14, 'Jugend', null, null),
+(22, 15, 'Eis Pflege', null, null),
+-- buehnefrei-ev (id=4)
+(23, null, 'Bühnefrei e.V.', null, null),
+(24, 23, 'Kiosk', null, null),
+(25, 23, 'Räumlichkeiten', null, null),
+(26, 23, 'Workshops', null, null),
+(27, 23, 'Projekte', null, null),
+(28, 27, 'Der kleine Lord', null, null),
+(29, 27, 'Das Hässliche Entlein', null, null),
+(30, 27, 'König der Löwen', null, null)
+;
+
+update Organization
+set rootBommel_id = 2
+where id = 2;
+
+update Organization
+set rootBommel_id = 11
+where id = 3;
+
+update Organization
+set rootBommel_id = 23
+where id = 4;
diff --git a/backend/app.hopps.org/src/test/java/app/hopps/org/delegates/CreationValidationDelegateTests.java b/backend/app.hopps.org/src/test/java/app/hopps/org/delegates/CreationValidationDelegateTests.java
index a21fe168..b4d5aab4 100644
--- a/backend/app.hopps.org/src/test/java/app/hopps/org/delegates/CreationValidationDelegateTests.java
+++ b/backend/app.hopps.org/src/test/java/app/hopps/org/delegates/CreationValidationDelegateTests.java
@@ -107,7 +107,7 @@ void shouldValidateUniqueness() throws Exception {
     }
 
     @Test
-    @DisplayName("should validate valid data")
+    @DisplayName("should invalidate non-unique slug")
     void shouldInvalidateUniqueness() {
 
         // given
@@ -117,6 +117,7 @@ void shouldInvalidateUniqueness() {
         existingOrganization.setSlug("kegelclub-777");
 
         QuarkusTransaction.begin();
+        organizationRepository.deleteAll();
         organizationRepository.persist(existingOrganization);
         QuarkusTransaction.commit();
 
diff --git a/backend/app.hopps.org/src/test/java/app/hopps/org/delegates/PersistOrganizationDelegateTests.java b/backend/app.hopps.org/src/test/java/app/hopps/org/delegates/PersistOrganizationDelegateTests.java
index 523ff7b5..5e6429d6 100644
--- a/backend/app.hopps.org/src/test/java/app/hopps/org/delegates/PersistOrganizationDelegateTests.java
+++ b/backend/app.hopps.org/src/test/java/app/hopps/org/delegates/PersistOrganizationDelegateTests.java
@@ -1,6 +1,10 @@
 package app.hopps.org.delegates;
 
-import app.hopps.org.jpa.*;
+import app.hopps.org.jpa.BommelRepository;
+import app.hopps.org.jpa.Member;
+import app.hopps.org.jpa.MemberRepository;
+import app.hopps.org.jpa.Organization;
+import app.hopps.org.jpa.OrganizationRepository;
 import io.quarkus.test.junit.QuarkusTest;
 import jakarta.inject.Inject;
 import jakarta.transaction.Transactional;
@@ -8,9 +12,7 @@
 import org.junit.jupiter.api.Test;
 
 import static org.hamcrest.MatcherAssert.assertThat;
-import static org.hamcrest.Matchers.equalTo;
-import static org.hamcrest.Matchers.hasItem;
-import static org.hamcrest.Matchers.hasProperty;
+import static org.hamcrest.Matchers.*;
 import static org.hamcrest.collection.IsIterableWithSize.iterableWithSize;
 
 @QuarkusTest
@@ -31,8 +33,8 @@ class PersistOrganizationDelegateTests {
     @BeforeEach
     @Transactional
     void cleanupDB() {
-        bommelRepository.deleteAll();
         organizationRepository.deleteAll();
+        bommelRepository.deleteAll();
         memberRepository.deleteAll();
     }
 
diff --git a/backend/app.hopps.org/src/test/java/app/hopps/org/jpa/BommelTest.java b/backend/app.hopps.org/src/test/java/app/hopps/org/jpa/BommelTest.java
index 5ce98ca3..2a8d94bd 100644
--- a/backend/app.hopps.org/src/test/java/app/hopps/org/jpa/BommelTest.java
+++ b/backend/app.hopps.org/src/test/java/app/hopps/org/jpa/BommelTest.java
@@ -5,6 +5,7 @@
 import io.quarkus.test.TestTransaction;
 import io.quarkus.test.junit.QuarkusTest;
 import jakarta.inject.Inject;
+import jakarta.transaction.Transactional;
 import jakarta.ws.rs.WebApplicationException;
 import org.flywaydb.core.Flyway;
 import org.instancio.Instancio;
@@ -35,9 +36,10 @@ class BommelTest {
     Flyway flyway;
 
     @BeforeEach
+    @Transactional
     public void cleanDatabase() {
-        flyway.clean();
-        flyway.migrate();
+        orgRepo.deleteAll();
+        repo.deleteAll();
     }
 
     @Test
@@ -106,14 +108,23 @@ void getChildrenWithCycle() {
     }
 
     @Test
-    @TestTransaction
     void simpleGetParentsTest() {
         // Arrange
-        var existingBommels = resourceCreator.setupSimpleTree();
-        var expectedParentsList = List.of(existingBommels.get(1), existingBommels.getFirst());
+        flyway.clean();
+        flyway.migrate();
+
+        // bommel with id=2 is root
+        // id=4 is child of id=2
+        // id=7 is child of id=4
+
+        var expectedParentsList = List.of(
+                repo.findById(4L),
+                repo.findById(2L));
+
+        var child = repo.findById(7L);
 
         // Act
-        List<TreeSearchBommel> treeSearchParents = repo.getParents(existingBommels.get(3));
+        List<TreeSearchBommel> treeSearchParents = repo.getParents(child);
 
         // Assert
         var actualParents = treeSearchParents.stream()
diff --git a/backend/app.hopps.org/src/test/java/app/hopps/org/rest/OrganizationResourceTests.java b/backend/app.hopps.org/src/test/java/app/hopps/org/rest/OrganizationResourceTests.java
index d3620382..8742778a 100644
--- a/backend/app.hopps.org/src/test/java/app/hopps/org/rest/OrganizationResourceTests.java
+++ b/backend/app.hopps.org/src/test/java/app/hopps/org/rest/OrganizationResourceTests.java
@@ -1,6 +1,9 @@
 package app.hopps.org.rest;
 
+import app.hopps.org.jpa.BommelRepository;
+import app.hopps.org.jpa.MemberRepository;
 import app.hopps.org.jpa.Organization;
+import app.hopps.org.jpa.OrganizationRepository;
 import app.hopps.org.rest.model.NewOrganizationInput;
 import app.hopps.org.rest.model.OrganizationInput;
 import app.hopps.org.rest.model.OwnerInput;
@@ -17,10 +20,8 @@
 
 import java.net.MalformedURLException;
 import java.net.URI;
-import java.util.Collections;
 
 import static io.restassured.RestAssured.given;
-import static io.restassured.RestAssured.when;
 import static org.hamcrest.Matchers.*;
 
 @QuarkusTest
@@ -30,6 +31,15 @@ class OrganizationResourceTests {
     @Inject
     Flyway flyway;
 
+    @Inject
+    OrganizationRepository organizationRepository;
+
+    @Inject
+    MemberRepository memberRepository;
+
+    @Inject
+    BommelRepository bommelRepository;
+
     @BeforeEach
     public void cleanDatabase() {
         flyway.clean();
@@ -78,6 +88,12 @@ void shouldInvalidateVereinWithoutName() {
 
     @Test
     void shouldStartCreatingOrganization() throws MalformedURLException {
+        QuarkusTransaction.begin();
+        organizationRepository.deleteAll();
+        bommelRepository.deleteAll();
+        memberRepository.deleteAll();
+        QuarkusTransaction.commit();
+
         OrganizationInput organizationInput = new OrganizationInput("Schützenverein", "schuetzenverein",
                 Organization.TYPE.EINGETRAGENER_VEREIN, URI.create("https://hopps.cloud").toURL(),
                 URI.create("https://hopps.cloud").toURL(), null);