diff --git a/testcontainers/pom.xml b/testcontainers/pom.xml
index e0168ae5fb36f5cafe5db93c29c783cd005e9575..2856e21b5ae722634d00b2d9c377082c627cf3b4 100644
--- a/testcontainers/pom.xml
+++ b/testcontainers/pom.xml
@@ -70,7 +70,7 @@
                 <artifactId>maven-surefire-plugin</artifactId>
                 <configuration>
                     <parallel>classes</parallel>
-                    <threadCount>10</threadCount>
+                    <threadCount>2</threadCount>
                 </configuration>
             </plugin>
         </plugins>
diff --git a/testcontainers/src/main/java/de/rieckpil/blog/testcontainers/PersonsController.java b/testcontainers/src/main/java/de/rieckpil/blog/testcontainers/PersonsController.java
index 58f53c02cb7050be6ecfdb44346b53ecc1106be1..0edd7cca1794b39651eb0249b3e6382019d41e24 100644
--- a/testcontainers/src/main/java/de/rieckpil/blog/testcontainers/PersonsController.java
+++ b/testcontainers/src/main/java/de/rieckpil/blog/testcontainers/PersonsController.java
@@ -22,6 +22,7 @@ public class PersonsController {
 
     @GetMapping("/{id}")
     public Person getPersonById(@PathVariable("id") Long id) {
+
         return personRepository.findById(id).orElseThrow(() -> new NoPersonFoundException("Person with id:" + id +
                 " not found"));
     }
diff --git a/testcontainers/src/test/java/de/rieckpil/blog/testcontainers/CreatePersonIntegrationTest.java b/testcontainers/src/test/java/de/rieckpil/blog/testcontainers/CreatePersonIntegrationTest.java
index e982a5bc9e83f36ab2eea97db72bc84c16f0929c..ff8a01938a59289145cc200f008ad306f6d0add6 100644
--- a/testcontainers/src/test/java/de/rieckpil/blog/testcontainers/CreatePersonIntegrationTest.java
+++ b/testcontainers/src/test/java/de/rieckpil/blog/testcontainers/CreatePersonIntegrationTest.java
@@ -1,16 +1,18 @@
 package de.rieckpil.blog.testcontainers;
 
-import org.junit.BeforeClass;
 import org.junit.ClassRule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.util.TestPropertyValues;
 import org.springframework.boot.test.web.client.TestRestTemplate;
 import org.springframework.boot.web.server.LocalServerPort;
+import org.springframework.context.ApplicationContextInitializer;
+import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.http.ResponseEntity;
+import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringRunner;
-import org.springframework.transaction.annotation.Transactional;
 import org.testcontainers.containers.PostgreSQLContainer;
 
 import java.util.HashMap;
@@ -21,7 +23,7 @@ import static org.junit.Assert.assertNotNull;
 
 @RunWith(SpringRunner.class)
 @SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
-@Transactional
+@ContextConfiguration(initializers = CreatePersonIntegrationTest.Initializer.class)
 public class CreatePersonIntegrationTest {
 
     @ClassRule
@@ -36,13 +38,17 @@ public class CreatePersonIntegrationTest {
 
     public TestRestTemplate testRestTemplate = new TestRestTemplate();
 
-    @BeforeClass
-    public static void beforeClass() {
-
-        System.setProperty("spring.datasource.url", postgreSQLContainer.getJdbcUrl());
-        System.setProperty("spring.datasource.password", postgreSQLContainer.getPassword());
-        System.setProperty("spring.datasource.username", postgreSQLContainer.getUsername());
-
+    public static class Initializer implements ApplicationContextInitializer<ConfigurableApplicationContext> {
+
+        @Override
+        public void initialize(ConfigurableApplicationContext configurableApplicationContext) {
+            TestPropertyValues values = TestPropertyValues.of(
+                    "spring.datasource.url=" + postgreSQLContainer.getJdbcUrl(),
+                    "spring.datasource.password=" + postgreSQLContainer.getPassword(),
+                    "spring.datasource.username=" + postgreSQLContainer.getUsername()
+            );
+            values.applyTo(configurableApplicationContext);
+        }
     }
 
     @Test
diff --git a/testcontainers/src/test/java/de/rieckpil/blog/testcontainers/DeletePersonIntegrationTest.java b/testcontainers/src/test/java/de/rieckpil/blog/testcontainers/DeletePersonIntegrationTest.java
index 03d06b24bc1c31b90c3aa4a7754e2d0b7e6afa69..742fe4465db29aa485384af857621114f8c18daa 100644
--- a/testcontainers/src/test/java/de/rieckpil/blog/testcontainers/DeletePersonIntegrationTest.java
+++ b/testcontainers/src/test/java/de/rieckpil/blog/testcontainers/DeletePersonIntegrationTest.java
@@ -1,16 +1,18 @@
 package de.rieckpil.blog.testcontainers;
 
-import org.junit.BeforeClass;
 import org.junit.ClassRule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.util.TestPropertyValues;
 import org.springframework.boot.test.web.client.TestRestTemplate;
 import org.springframework.boot.web.server.LocalServerPort;
+import org.springframework.context.ApplicationContextInitializer;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.jdbc.Sql;
 import org.springframework.test.context.junit4.SpringRunner;
-import org.springframework.transaction.annotation.Transactional;
 import org.testcontainers.containers.PostgreSQLContainer;
 
 import static org.junit.Assert.assertEquals;
@@ -18,7 +20,7 @@ import static org.junit.Assert.assertFalse;
 
 @RunWith(SpringRunner.class)
 @SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
-@Transactional
+@ContextConfiguration(initializers = DeletePersonIntegrationTest.Initializer.class)
 public class DeletePersonIntegrationTest {
 
     @ClassRule
@@ -33,14 +35,17 @@ public class DeletePersonIntegrationTest {
 
     public TestRestTemplate testRestTemplate = new TestRestTemplate();
 
-    @BeforeClass
-    public static void beforeClass() {
-
-        System.out.println(postgreSQLContainer.getJdbcUrl());
-        System.setProperty("spring.datasource.url", postgreSQLContainer.getJdbcUrl());
-        System.setProperty("spring.datasource.password", postgreSQLContainer.getPassword());
-        System.setProperty("spring.datasource.username", postgreSQLContainer.getUsername());
-
+    public static class Initializer implements ApplicationContextInitializer<ConfigurableApplicationContext> {
+
+        @Override
+        public void initialize(ConfigurableApplicationContext configurableApplicationContext) {
+            TestPropertyValues values = TestPropertyValues.of(
+                    "spring.datasource.url=" + postgreSQLContainer.getJdbcUrl(),
+                    "spring.datasource.password=" + postgreSQLContainer.getPassword(),
+                    "spring.datasource.username=" + postgreSQLContainer.getUsername()
+            );
+            values.applyTo(configurableApplicationContext);
+        }
     }
 
     @Test
diff --git a/testcontainers/src/test/java/de/rieckpil/blog/testcontainers/GetAllPersonsIntegrationTest.java b/testcontainers/src/test/java/de/rieckpil/blog/testcontainers/GetAllPersonsIntegrationTest.java
index 22f6956dfb309aa1422612e143a64984bc551bcf..d185408a5f4fa737456fabac9066bb1bf27faadd 100644
--- a/testcontainers/src/test/java/de/rieckpil/blog/testcontainers/GetAllPersonsIntegrationTest.java
+++ b/testcontainers/src/test/java/de/rieckpil/blog/testcontainers/GetAllPersonsIntegrationTest.java
@@ -1,17 +1,19 @@
 package de.rieckpil.blog.testcontainers;
 
-import org.junit.BeforeClass;
 import org.junit.ClassRule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.util.TestPropertyValues;
 import org.springframework.boot.test.web.client.TestRestTemplate;
 import org.springframework.boot.web.server.LocalServerPort;
+import org.springframework.context.ApplicationContextInitializer;
+import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.http.ResponseEntity;
+import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.jdbc.Sql;
 import org.springframework.test.context.junit4.SpringRunner;
-import org.springframework.transaction.annotation.Transactional;
 import org.testcontainers.containers.PostgreSQLContainer;
 
 import java.util.Arrays;
@@ -23,7 +25,7 @@ import static org.junit.Assert.assertTrue;
 
 @RunWith(SpringRunner.class)
 @SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
-@Transactional
+@ContextConfiguration(initializers = GetAllPersonsIntegrationTest.Initializer.class)
 public class GetAllPersonsIntegrationTest {
 
     @ClassRule
@@ -38,14 +40,17 @@ public class GetAllPersonsIntegrationTest {
 
     public TestRestTemplate testRestTemplate = new TestRestTemplate();
 
-    @BeforeClass
-    public static void beforeClass() {
-
-        System.out.println(postgreSQLContainer.getJdbcUrl());
-        System.setProperty("spring.datasource.url", postgreSQLContainer.getJdbcUrl());
-        System.setProperty("spring.datasource.password", postgreSQLContainer.getPassword());
-        System.setProperty("spring.datasource.username", postgreSQLContainer.getUsername());
-
+    public static class Initializer implements ApplicationContextInitializer<ConfigurableApplicationContext> {
+
+        @Override
+        public void initialize(ConfigurableApplicationContext configurableApplicationContext) {
+            TestPropertyValues values = TestPropertyValues.of(
+                    "spring.datasource.url=" + postgreSQLContainer.getJdbcUrl(),
+                    "spring.datasource.password=" + postgreSQLContainer.getPassword(),
+                    "spring.datasource.username=" + postgreSQLContainer.getUsername()
+            );
+            values.applyTo(configurableApplicationContext);
+        }
     }
 
     @Test
diff --git a/testcontainers/src/test/java/de/rieckpil/blog/testcontainers/GetPersonByIdIntegrationTest.java b/testcontainers/src/test/java/de/rieckpil/blog/testcontainers/GetPersonByIdIntegrationTest.java
index 84c980406f4363d46f6b66ad13a0a9e9c25bcd40..45357e267bcf433b43219133624eda4d6e032666 100644
--- a/testcontainers/src/test/java/de/rieckpil/blog/testcontainers/GetPersonByIdIntegrationTest.java
+++ b/testcontainers/src/test/java/de/rieckpil/blog/testcontainers/GetPersonByIdIntegrationTest.java
@@ -1,19 +1,20 @@
 package de.rieckpil.blog.testcontainers;
 
-import org.junit.BeforeClass;
 import org.junit.ClassRule;
-import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.util.TestPropertyValues;
 import org.springframework.boot.test.web.client.TestRestTemplate;
 import org.springframework.boot.web.server.LocalServerPort;
+import org.springframework.context.ApplicationContextInitializer;
+import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
+import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.jdbc.Sql;
 import org.springframework.test.context.junit4.SpringRunner;
-import org.springframework.transaction.annotation.Transactional;
 import org.testcontainers.containers.PostgreSQLContainer;
 
 import static org.junit.Assert.assertEquals;
@@ -21,7 +22,7 @@ import static org.junit.Assert.assertNull;
 
 @RunWith(SpringRunner.class)
 @SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
-@Transactional
+@ContextConfiguration(initializers = GetPersonByIdIntegrationTest.Initializer.class)
 public class GetPersonByIdIntegrationTest {
 
     @ClassRule
@@ -36,13 +37,28 @@ public class GetPersonByIdIntegrationTest {
 
     public TestRestTemplate testRestTemplate = new TestRestTemplate();
 
-    @BeforeClass
-    public static void beforeClass() {
+    public static class Initializer implements ApplicationContextInitializer<ConfigurableApplicationContext> {
+
+        @Override
+        public void initialize(ConfigurableApplicationContext configurableApplicationContext) {
+            TestPropertyValues values = TestPropertyValues.of(
+                    "spring.datasource.url=" + postgreSQLContainer.getJdbcUrl(),
+                    "spring.datasource.password=" + postgreSQLContainer.getPassword(),
+                    "spring.datasource.username=" + postgreSQLContainer.getUsername()
+            );
+            values.applyTo(configurableApplicationContext);
+        }
+    }
+
+    @Test
+    public void testNotExistingPersonByIdShouldReturn404() {
+
+        ResponseEntity<Person> result = testRestTemplate.getForEntity("http://localhost:" + localPort +
+                "/api/persons/42", Person.class);
 
-        System.out.println(postgreSQLContainer.getJdbcUrl());
-        System.setProperty("spring.datasource.url", postgreSQLContainer.getJdbcUrl());
-        System.setProperty("spring.datasource.password", postgreSQLContainer.getPassword());
-        System.setProperty("spring.datasource.username", postgreSQLContainer.getUsername());
+        assertEquals(HttpStatus.NOT_FOUND, result.getStatusCode());
+        assertNull(result.getBody().getName());
+        assertNull(result.getBody().getId());
 
     }
 
@@ -50,6 +66,9 @@ public class GetPersonByIdIntegrationTest {
     @Sql("/testdata/FILL_FOUR_PERSONS.sql")
     public void testExistingPersonById() {
 
+        System.out.println(personRepository.findAll().size());
+
+
         ResponseEntity<Person> result = testRestTemplate.getForEntity("http://localhost:" + localPort +
                 "/api/persons/1", Person.class);
 
@@ -61,17 +80,4 @@ public class GetPersonByIdIntegrationTest {
 
     }
 
-    @Test
-    public void testNotExistingPersonByIdShouldReturn404() {
-
-        personRepository.deleteAll();
-
-        ResponseEntity<Person> result = testRestTemplate.getForEntity("http://localhost:" + localPort +
-                "/api/persons/42", Person.class);
-
-        assertEquals(HttpStatus.NOT_FOUND, result.getStatusCode());
-        assertNull(result.getBody().getName());
-        assertNull(result.getBody().getId());
-
-    }
 }
diff --git a/testcontainers/src/test/java/de/rieckpil/blog/testcontainers/TestcontainersApplicationTests.java b/testcontainers/src/test/java/de/rieckpil/blog/testcontainers/TestcontainersApplicationTests.java
index aea218d5cb5e74d58fb7e6bfafa01769434c09a8..aae2634aa42c2aae8af5b925d57ae5178be406cf 100644
--- a/testcontainers/src/test/java/de/rieckpil/blog/testcontainers/TestcontainersApplicationTests.java
+++ b/testcontainers/src/test/java/de/rieckpil/blog/testcontainers/TestcontainersApplicationTests.java
@@ -1,30 +1,36 @@
 package de.rieckpil.blog.testcontainers;
 
-import org.junit.BeforeClass;
 import org.junit.ClassRule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.util.TestPropertyValues;
+import org.springframework.context.ApplicationContextInitializer;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringRunner;
-import org.springframework.transaction.annotation.Transactional;
 import org.testcontainers.containers.PostgreSQLContainer;
 
 @RunWith(SpringRunner.class)
 @SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
-@Transactional
+@ContextConfiguration(initializers = TestcontainersApplicationTests.Initializer.class)
 public class TestcontainersApplicationTests {
 
     @ClassRule
     public static PostgreSQLContainer postgreSQLContainer = new PostgreSQLContainer().withPassword("inmemory")
             .withUsername("inmemory");
 
-    @BeforeClass
-    public static void beforeClass() {
-
-        System.setProperty("spring.datasource.url", postgreSQLContainer.getJdbcUrl());
-        System.setProperty("spring.datasource.password", postgreSQLContainer.getPassword());
-        System.setProperty("spring.datasource.username", postgreSQLContainer.getUsername());
-
+    public static class Initializer implements ApplicationContextInitializer<ConfigurableApplicationContext> {
+
+        @Override
+        public void initialize(ConfigurableApplicationContext configurableApplicationContext) {
+            TestPropertyValues values = TestPropertyValues.of(
+                    "spring.datasource.url=" + postgreSQLContainer.getJdbcUrl(),
+                    "spring.datasource.password=" + postgreSQLContainer.getPassword(),
+                    "spring.datasource.username=" + postgreSQLContainer.getUsername()
+            );
+            values.applyTo(configurableApplicationContext);
+        }
     }
 
     @Test