diff --git a/build.gradle b/build.gradle
index 8222161fafc..3e3205faad0 100644
--- a/build.gradle
+++ b/build.gradle
@@ -513,7 +513,7 @@ dependencies {
   // https://mvnrepository.com/artifact/org.awaitility/awaitility-proxy
   testImplementation group: 'org.awaitility', name: 'awaitility-proxy', version: '3.1.6'
   testImplementation 'io.github.hakky54:logcaptor:2.12.6'
-  testImplementation 'org.testcontainers:testcontainers:1.21.4'
+  testImplementation 'org.testcontainers:testcontainers:2.0.5'
 
   testImplementation group: 'org.jeasy', name: 'easy-random-core', version: '5.0.0'
 
diff --git a/src/functionalTest/java/uk/gov/hmcts/darts/common/HiddenReasonFunctionalTest.java b/src/functionalTest/java/uk/gov/hmcts/darts/common/HiddenReasonFunctionalTest.java
index b6a7e2ab37c..e0d36ddbd4e 100644
--- a/src/functionalTest/java/uk/gov/hmcts/darts/common/HiddenReasonFunctionalTest.java
+++ b/src/functionalTest/java/uk/gov/hmcts/darts/common/HiddenReasonFunctionalTest.java
@@ -10,7 +10,7 @@
 
 import java.util.List;
 
-import static org.junit.Assert.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
 class HiddenReasonFunctionalTest extends FunctionalTest {
 
diff --git a/src/integrationTest/java/uk/gov/hmcts/darts/arm/rpo/DownloadProductionServiceIntTest.java b/src/integrationTest/java/uk/gov/hmcts/darts/arm/rpo/DownloadProductionServiceIntTest.java
index 9af6041ce6d..6fd039a894d 100644
--- a/src/integrationTest/java/uk/gov/hmcts/darts/arm/rpo/DownloadProductionServiceIntTest.java
+++ b/src/integrationTest/java/uk/gov/hmcts/darts/arm/rpo/DownloadProductionServiceIntTest.java
@@ -18,9 +18,9 @@
 
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.containsString;
-import static org.junit.Assert.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
diff --git a/src/integrationTest/java/uk/gov/hmcts/darts/arm/rpo/GetIndexesByMatterIdServiceIntTest.java b/src/integrationTest/java/uk/gov/hmcts/darts/arm/rpo/GetIndexesByMatterIdServiceIntTest.java
index 2c29d3ba5f2..48b1a5182f8 100644
--- a/src/integrationTest/java/uk/gov/hmcts/darts/arm/rpo/GetIndexesByMatterIdServiceIntTest.java
+++ b/src/integrationTest/java/uk/gov/hmcts/darts/arm/rpo/GetIndexesByMatterIdServiceIntTest.java
@@ -19,9 +19,9 @@
 
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.containsString;
-import static org.junit.Assert.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.when;
 
diff --git a/src/integrationTest/java/uk/gov/hmcts/darts/arm/rpo/RemoveProductionServiceIntTest.java b/src/integrationTest/java/uk/gov/hmcts/darts/arm/rpo/RemoveProductionServiceIntTest.java
index 8c1fa636e83..cff282904fb 100644
--- a/src/integrationTest/java/uk/gov/hmcts/darts/arm/rpo/RemoveProductionServiceIntTest.java
+++ b/src/integrationTest/java/uk/gov/hmcts/darts/arm/rpo/RemoveProductionServiceIntTest.java
@@ -16,8 +16,8 @@
 
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.containsString;
-import static org.junit.Assert.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.when;
 
diff --git a/src/integrationTest/java/uk/gov/hmcts/darts/audio/controller/AudioControllerAddAudioMetadataIntTest.java b/src/integrationTest/java/uk/gov/hmcts/darts/audio/controller/AudioControllerAddAudioMetadataIntTest.java
index f562bda0bf2..2e06bd86da5 100644
--- a/src/integrationTest/java/uk/gov/hmcts/darts/audio/controller/AudioControllerAddAudioMetadataIntTest.java
+++ b/src/integrationTest/java/uk/gov/hmcts/darts/audio/controller/AudioControllerAddAudioMetadataIntTest.java
@@ -57,9 +57,9 @@
 import java.util.function.Function;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.junit.Assert.assertNotEquals;
-import static org.junit.Assert.assertNull;
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.mockito.Mockito.when;
 import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
diff --git a/src/integrationTest/java/uk/gov/hmcts/darts/audio/service/impl/MediaRequestServiceTest.java b/src/integrationTest/java/uk/gov/hmcts/darts/audio/service/impl/MediaRequestServiceTest.java
index d6f685c2a1a..6aa27101ad3 100644
--- a/src/integrationTest/java/uk/gov/hmcts/darts/audio/service/impl/MediaRequestServiceTest.java
+++ b/src/integrationTest/java/uk/gov/hmcts/darts/audio/service/impl/MediaRequestServiceTest.java
@@ -24,9 +24,9 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.within;
-import static org.junit.Assert.assertNotEquals;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
diff --git a/src/integrationTest/java/uk/gov/hmcts/darts/cases/controller/CaseControllerAdminGetCaseByIdIntTest.java b/src/integrationTest/java/uk/gov/hmcts/darts/cases/controller/CaseControllerAdminGetCaseByIdIntTest.java
index 200b726b8cd..68b663c33c6 100644
--- a/src/integrationTest/java/uk/gov/hmcts/darts/cases/controller/CaseControllerAdminGetCaseByIdIntTest.java
+++ b/src/integrationTest/java/uk/gov/hmcts/darts/cases/controller/CaseControllerAdminGetCaseByIdIntTest.java
@@ -134,8 +134,8 @@ void adminGetCaseById_WithCaseOpenAndReportingRestrictions() throws Exception {
         String actualResponse = mvcResult.getResponse().getContentAsString();
         String expectedResponse = getContentsFromFile(
             "tests/cases/CaseControllerAdminGetCaseByIdTest/testCaseOpen/expectedResponse.json");
-        expectedResponse = expectedResponse.replace("<CREATED_AT>", courtCase.getCreatedDateTime().format(DateTimeFormatter.ISO_DATE_TIME));
-        expectedResponse = expectedResponse.replace("<LAST_MODIFIED_AT>", courtCase.getLastModifiedDateTime().format(DateTimeFormatter.ISO_DATE_TIME));
+        expectedResponse = expectedResponse.replace("<CREATED_AT>", formatAsUtc(courtCase.getCreatedDateTime()));
+        expectedResponse = expectedResponse.replace("<LAST_MODIFIED_AT>", formatAsUtc(courtCase.getLastModifiedDateTime()));
         JSONAssert.assertEquals(expectedResponse, actualResponse, JSONCompareMode.NON_EXTENSIBLE);
 
     }
@@ -176,8 +176,8 @@ void adminGetCaseById_WithCaseClosedAndReportingRestrictions() throws Exception
         String actualResponse = mvcResult.getResponse().getContentAsString();
         String expectedResponse = getContentsFromFile(
             "tests/cases/CaseControllerAdminGetCaseByIdTest/testCaseClosed/expectedResponse.json");
-        expectedResponse = expectedResponse.replace("<CREATED_AT>", courtCase.getCreatedDateTime().format(DateTimeFormatter.ISO_DATE_TIME));
-        expectedResponse = expectedResponse.replace("<LAST_MODIFIED_AT>", courtCase.getLastModifiedDateTime().format(DateTimeFormatter.ISO_DATE_TIME));
+        expectedResponse = expectedResponse.replace("<CREATED_AT>", formatAsUtc(courtCase.getCreatedDateTime()));
+        expectedResponse = expectedResponse.replace("<LAST_MODIFIED_AT>", formatAsUtc(courtCase.getLastModifiedDateTime()));
         JSONAssert.assertEquals(expectedResponse, actualResponse, JSONCompareMode.NON_EXTENSIBLE);
 
     }
@@ -213,8 +213,8 @@ void adminGetCaseById_IsAnonymised() throws Exception {
         String expectedResponse = getContentsFromFile(
             "tests/cases/CaseControllerAdminGetCaseByIdTest/testIsAnonymised/expectedResponse.json");
         expectedResponse = expectedResponse
-            .replace("<CREATED_AT>", courtCase.getCreatedDateTime().format(DateTimeFormatter.ISO_DATE_TIME))
-            .replace("<LAST_MODIFIED_AT>", courtCase.getLastModifiedDateTime().format(DateTimeFormatter.ISO_DATE_TIME))
+            .replace("<CREATED_AT>", formatAsUtc(courtCase.getCreatedDateTime()))
+            .replace("<LAST_MODIFIED_AT>", formatAsUtc(courtCase.getLastModifiedDateTime()))
             .replace("<DATA_ANONYMISED_BY>", String.valueOf(anonymisedBy.getId()));
         JSONAssert.assertEquals(expectedResponse, actualResponse, JSONCompareMode.NON_EXTENSIBLE);
     }
@@ -248,8 +248,8 @@ void adminGetCaseById_IsDeleted() throws Exception {
         String expectedResponse = getContentsFromFile(
             "tests/cases/CaseControllerAdminGetCaseByIdTest/expectedResponse_isDeleted.json");
         expectedResponse = expectedResponse
-            .replace("<CREATED_AT>", courtCase.getCreatedDateTime().format(DateTimeFormatter.ISO_DATE_TIME))
-            .replace("<LAST_MODIFIED_AT>", courtCase.getLastModifiedDateTime().format(DateTimeFormatter.ISO_DATE_TIME))
+            .replace("<CREATED_AT>", formatAsUtc(courtCase.getCreatedDateTime()))
+            .replace("<LAST_MODIFIED_AT>", formatAsUtc(courtCase.getLastModifiedDateTime()))
             .replace("<CASE_DELETED_BY>", String.valueOf(deletedBy.getId()));
         JSONAssert.assertEquals(expectedResponse, actualResponse, JSONCompareMode.NON_EXTENSIBLE);
     }
@@ -299,8 +299,8 @@ void adminGetCaseById_WithRetentionAndAdditionalCaseDetails() throws Exception {
         String expectedResponse = getContentsFromFile(
             "tests/cases/CaseControllerAdminGetCaseByIdTest/expectedResponse_withRetentionAndAdditionalCaseDetails.json");
         expectedResponse = expectedResponse
-            .replace("<CREATED_AT>", courtCase.getCreatedDateTime().format(DateTimeFormatter.ISO_DATE_TIME))
-            .replace("<LAST_MODIFIED_AT>", courtCase.getLastModifiedDateTime().format(DateTimeFormatter.ISO_DATE_TIME));
+            .replace("<CREATED_AT>", formatAsUtc(courtCase.getCreatedDateTime()))
+            .replace("<LAST_MODIFIED_AT>", formatAsUtc(courtCase.getLastModifiedDateTime()));
         JSONAssert.assertEquals(expectedResponse, actualResponse, JSONCompareMode.NON_EXTENSIBLE);
     }
 
@@ -328,4 +328,8 @@ private List<EventEntity> createEventsWithDifferentTimestamps(List<OffsetDateTim
                 return event;
             }).toList();
     }
+
+    private static String formatAsUtc(OffsetDateTime dateTime) {
+        return dateTime.withOffsetSameInstant(UTC).format(DateTimeFormatter.ISO_DATE_TIME);
+    }
 }
diff --git a/src/integrationTest/java/uk/gov/hmcts/darts/task/runner/impl/AssociatedObjectDataExpiryDeletionAutomatedTaskIntTest.java b/src/integrationTest/java/uk/gov/hmcts/darts/task/runner/impl/AssociatedObjectDataExpiryDeletionAutomatedTaskIntTest.java
index 9ff64f4e1ef..644aea8ad8b 100644
--- a/src/integrationTest/java/uk/gov/hmcts/darts/task/runner/impl/AssociatedObjectDataExpiryDeletionAutomatedTaskIntTest.java
+++ b/src/integrationTest/java/uk/gov/hmcts/darts/task/runner/impl/AssociatedObjectDataExpiryDeletionAutomatedTaskIntTest.java
@@ -2,12 +2,12 @@
 
 import lombok.RequiredArgsConstructor;
 import lombok.SneakyThrows;
+import org.apache.commons.lang3.function.TriFunction;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.data.jpa.domain.Specification;
 import org.springframework.test.context.TestPropertySource;
-import org.testcontainers.shaded.org.apache.commons.lang3.function.TriFunction;
 import uk.gov.hmcts.darts.audit.api.AuditActivity;
 import uk.gov.hmcts.darts.common.entity.AnnotationDocumentEntity;
 import uk.gov.hmcts.darts.common.entity.AnnotationEntity;
diff --git a/src/test/java/uk/gov/hmcts/darts/arm/service/impl/DeleteArmResponseFilesHelperImplTest.java b/src/test/java/uk/gov/hmcts/darts/arm/service/impl/DeleteArmResponseFilesHelperImplTest.java
index 7dcf2899b98..7c4e96c228c 100644
--- a/src/test/java/uk/gov/hmcts/darts/arm/service/impl/DeleteArmResponseFilesHelperImplTest.java
+++ b/src/test/java/uk/gov/hmcts/darts/arm/service/impl/DeleteArmResponseFilesHelperImplTest.java
@@ -21,7 +21,7 @@
 import java.util.List;
 import java.util.Optional;
 
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
diff --git a/src/test/java/uk/gov/hmcts/darts/arm/service/impl/DetsToArmBatchProcessResponseFilesImplTest.java b/src/test/java/uk/gov/hmcts/darts/arm/service/impl/DetsToArmBatchProcessResponseFilesImplTest.java
index 1d2a4f0629b..5f82e8f5716 100644
--- a/src/test/java/uk/gov/hmcts/darts/arm/service/impl/DetsToArmBatchProcessResponseFilesImplTest.java
+++ b/src/test/java/uk/gov/hmcts/darts/arm/service/impl/DetsToArmBatchProcessResponseFilesImplTest.java
@@ -39,9 +39,9 @@
 import java.time.format.DateTimeFormatter;
 import java.util.Optional;
 
-import static org.junit.Assert.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.mockito.ArgumentMatchers.anyLong;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
diff --git a/src/test/java/uk/gov/hmcts/darts/arm/util/ArmRpoJsonUtilTest.java b/src/test/java/uk/gov/hmcts/darts/arm/util/ArmRpoJsonUtilTest.java
index 0614de3d7b4..cb62a9078f3 100644
--- a/src/test/java/uk/gov/hmcts/darts/arm/util/ArmRpoJsonUtilTest.java
+++ b/src/test/java/uk/gov/hmcts/darts/arm/util/ArmRpoJsonUtilTest.java
@@ -2,8 +2,8 @@
 
 import org.junit.jupiter.api.Test;
 
-import static org.junit.Assert.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 class ArmRpoJsonUtilTest {
 
diff --git a/src/test/java/uk/gov/hmcts/darts/cases/service/impl/CloseOldCasesProcessorImplTest.java b/src/test/java/uk/gov/hmcts/darts/cases/service/impl/CloseOldCasesProcessorImplTest.java
index 9b35f200a6a..48ddb0da45d 100644
--- a/src/test/java/uk/gov/hmcts/darts/cases/service/impl/CloseOldCasesProcessorImplTest.java
+++ b/src/test/java/uk/gov/hmcts/darts/cases/service/impl/CloseOldCasesProcessorImplTest.java
@@ -30,10 +30,10 @@
 import java.time.ZoneOffset;
 import java.util.List;
 
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.lenient;
 import static org.mockito.Mockito.when;
diff --git a/src/test/java/uk/gov/hmcts/darts/usermanagement/service/impl/usermanagement/service/UserManagementServiceImplTest.java b/src/test/java/uk/gov/hmcts/darts/usermanagement/service/impl/usermanagement/service/UserManagementServiceImplTest.java
index cdc5f86456c..8bfeaeaba23 100644
--- a/src/test/java/uk/gov/hmcts/darts/usermanagement/service/impl/usermanagement/service/UserManagementServiceImplTest.java
+++ b/src/test/java/uk/gov/hmcts/darts/usermanagement/service/impl/usermanagement/service/UserManagementServiceImplTest.java
@@ -44,8 +44,8 @@
 import java.util.Optional;
 import java.util.Set;
 
-import static org.junit.Assert.assertNull;
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.mockito.ArgumentMatchers.argThat;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
diff --git a/src/testCommon/java/uk/gov/hmcts/darts/test/common/DataGenerator.java b/src/testCommon/java/uk/gov/hmcts/darts/test/common/DataGenerator.java
index 0f8cd26f3d2..fe49b33bbb4 100644
--- a/src/testCommon/java/uk/gov/hmcts/darts/test/common/DataGenerator.java
+++ b/src/testCommon/java/uk/gov/hmcts/darts/test/common/DataGenerator.java
@@ -4,8 +4,8 @@
 import lombok.RequiredArgsConstructor;
 import org.apache.commons.codec.DecoderException;
 import org.apache.commons.codec.binary.Hex;
+import org.apache.commons.lang3.RandomUtils;
 import org.springframework.util.unit.DataSize;
-import org.testcontainers.shaded.org.apache.commons.lang3.RandomUtils;
 
 import java.io.ByteArrayOutputStream;
 import java.io.File;
@@ -75,7 +75,7 @@ public static byte[] createUniqueData(DataSize dataSize, FileType fileType) {
         final ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
         byteArrayOutputStream.writeBytes(signatureBytes);
 
-        byte[] randomisedBytes = RandomUtils.nextBytes(contentSize);
+        byte[] randomisedBytes = RandomUtils.insecure().randomBytes(contentSize);
         byteArrayOutputStream.writeBytes(randomisedBytes);
 
         return byteArrayOutputStream.toByteArray();
diff --git a/src/testCommon/java/uk/gov/hmcts/darts/test/common/DataGeneratorTest.java b/src/testCommon/java/uk/gov/hmcts/darts/test/common/DataGeneratorTest.java
index 90a3901e941..0bff7dcf272 100644
--- a/src/testCommon/java/uk/gov/hmcts/darts/test/common/DataGeneratorTest.java
+++ b/src/testCommon/java/uk/gov/hmcts/darts/test/common/DataGeneratorTest.java
@@ -2,19 +2,19 @@
 
 
 import org.apache.tika.Tika;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 import org.springframework.util.unit.DataSize;
 
 import java.io.IOException;
 import java.nio.file.Path;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
-public class DataGeneratorTest {
+class DataGeneratorTest {
 
     @Test
-    public void shouldProduceAValidMP2() throws IOException {
+    void shouldProduceAValidMP2() throws IOException {
         Path audioFile = DataGenerator.createUniqueFile(DataSize.ofBytes(100), DataGenerator.FileType.MP2);
 
         assertEquals(100, audioFile.toFile().length());
@@ -22,7 +22,7 @@ public void shouldProduceAValidMP2() throws IOException {
     }
 
     @Test
-    public void shouldProduceAValidMP3() throws IOException {
+    void shouldProduceAValidMP3() throws IOException {
         Path uniqueAudioFile = DataGenerator.createUniqueFile(DataSize.ofBytes(100), DataGenerator.FileType.MP3);
 
         assertEquals(100, uniqueAudioFile.toFile().length());
@@ -30,7 +30,7 @@ public void shouldProduceAValidMP3() throws IOException {
     }
 
     @Test
-    public void showThrowExceptionIfDesiredLengthIsTooSmall() {
+    void showThrowExceptionIfDesiredLengthIsTooSmall() {
         IllegalArgumentException illegalArgumentException = assertThrows(IllegalArgumentException.class, () ->
             DataGenerator.createUniqueFile(DataSize.ofBytes(1), DataGenerator.FileType.MP2)
         );