diff --git a/api/src/main/java/io/kafbat/ui/controller/AccessController.java b/api/src/main/java/io/kafbat/ui/controller/AccessController.java
index 5833f2e3c..e5b1ea438 100644
--- a/api/src/main/java/io/kafbat/ui/controller/AccessController.java
+++ b/api/src/main/java/io/kafbat/ui/controller/AccessController.java
@@ -45,33 +45,34 @@ public Mono<ResponseEntity<AuthenticationInfoDTO>> getUserAuthInfo(ServerWebExch
         .map(SecurityContext::getAuthentication)
         .map(Principal::getName);
 
+    var builder = AuthenticationInfoDTO.builder()
+        .rbacEnabled(accessControlService.isRbacEnabled());
+
     return userName
         .zipWith(permissions)
-        .map(data -> {
-          var dto = new AuthenticationInfoDTO(accessControlService.isRbacEnabled());
-          dto.setUserInfo(new UserInfoDTO(data.getT1(), data.getT2()));
-          return dto;
-        })
-        .switchIfEmpty(Mono.just(new AuthenticationInfoDTO(accessControlService.isRbacEnabled())))
+        .map(data -> (AuthenticationInfoDTO) builder
+            .userInfo(new UserInfoDTO(data.getT1(), data.getT2()))
+            .build()
+        )
+        .switchIfEmpty(Mono.just(builder.build()))
         .map(ResponseEntity::ok);
   }
 
   private List<UserPermissionDTO> mapPermissions(List<Permission> permissions, List<String> clusters) {
     return permissions
         .stream()
-        .map(permission -> {
-          UserPermissionDTO dto = new UserPermissionDTO();
-          dto.setClusters(clusters);
-          dto.setResource(ResourceTypeDTO.fromValue(permission.getResource().toString().toUpperCase()));
-          dto.setValue(permission.getValue());
-          dto.setActions(permission.getParsedActions()
-              .stream()
-              .map(p -> p.name().toUpperCase())
-              .map(this::mapAction)
-              .filter(Objects::nonNull)
-              .toList());
-          return dto;
-        })
+        .map(permission -> (UserPermissionDTO) UserPermissionDTO.builder()
+            .clusters(clusters)
+            .resource(ResourceTypeDTO.fromValue(permission.getResource().toString().toUpperCase()))
+            .value(permission.getValue())
+            .actions(permission.getParsedActions()
+                .stream()
+                .map(p -> p.name().toUpperCase())
+                .map(this::mapAction)
+                .filter(Objects::nonNull)
+                .toList())
+            .build()
+        )
         .toList();
   }
 
diff --git a/api/src/main/java/io/kafbat/ui/controller/KsqlController.java b/api/src/main/java/io/kafbat/ui/controller/KsqlController.java
index 6c633ee2c..d8b3203a9 100644
--- a/api/src/main/java/io/kafbat/ui/controller/KsqlController.java
+++ b/api/src/main/java/io/kafbat/ui/controller/KsqlController.java
@@ -53,6 +53,7 @@ public Mono<ResponseEntity<KsqlCommandV2ResponseDTO>> executeKsql(String cluster
   }
 
   @Override
+  @SuppressWarnings("unchecked")
   public Mono<ResponseEntity<Flux<KsqlResponseDTO>>> openKsqlResponsePipe(String clusterName,
                                                                           String pipeId,
                                                                           ServerWebExchange exchange) {
diff --git a/api/src/main/java/io/kafbat/ui/controller/TopicsController.java b/api/src/main/java/io/kafbat/ui/controller/TopicsController.java
index 53e9fc8cd..6ccfd18fd 100644
--- a/api/src/main/java/io/kafbat/ui/controller/TopicsController.java
+++ b/api/src/main/java/io/kafbat/ui/controller/TopicsController.java
@@ -350,18 +350,12 @@ private Comparator<InternalTopic> getComparatorForTopic(
     if (orderBy == null) {
       return defaultComparator;
     }
-    switch (orderBy) {
-      case TOTAL_PARTITIONS:
-        return Comparator.comparing(InternalTopic::getPartitionCount);
-      case OUT_OF_SYNC_REPLICAS:
-        return Comparator.comparing(t -> t.getReplicas() - t.getInSyncReplicas());
-      case REPLICATION_FACTOR:
-        return Comparator.comparing(InternalTopic::getReplicationFactor);
-      case SIZE:
-        return Comparator.comparing(InternalTopic::getSegmentSize);
-      case NAME:
-      default:
-        return defaultComparator;
-    }
+    return switch (orderBy) {
+      case TOTAL_PARTITIONS -> Comparator.comparing(InternalTopic::getPartitionCount);
+      case OUT_OF_SYNC_REPLICAS -> Comparator.comparing(t -> t.getReplicas() - t.getInSyncReplicas());
+      case REPLICATION_FACTOR -> Comparator.comparing(InternalTopic::getReplicationFactor);
+      case SIZE -> Comparator.comparing(InternalTopic::getSegmentSize);
+      default -> defaultComparator;
+    };
   }
 }
diff --git a/api/src/test/java/io/kafbat/ui/emitter/MessageFiltersTest.java b/api/src/test/java/io/kafbat/ui/emitter/MessageFiltersTest.java
index cae8629eb..617cfb0c1 100644
--- a/api/src/test/java/io/kafbat/ui/emitter/MessageFiltersTest.java
+++ b/api/src/test/java/io/kafbat/ui/emitter/MessageFiltersTest.java
@@ -199,6 +199,10 @@ void testBase64DecodingWorks() {
   }
 
   private TopicMessageDTO msg() {
-    return new TopicMessageDTO(1, -1L, OffsetDateTime.now());
+    return TopicMessageDTO.builder()
+        .partition(1)
+        .offset(-1L)
+        .timestamp(OffsetDateTime.now())
+        .build();
   }
 }
diff --git a/contract/pom.xml b/contract/pom.xml
index 994185c96..8d7e76cea 100644
--- a/contract/pom.xml
+++ b/contract/pom.xml
@@ -46,6 +46,11 @@
                     <artifactId>javax.annotation-api</artifactId>
                     <version>1.3.2</version>
                 </dependency>
+                <dependency>
+                    <groupId>org.projectlombok</groupId>
+                    <artifactId>lombok</artifactId>
+                    <version>${org.projectlombok.version}</version>
+                </dependency>
             </dependencies>
 
             <build>
@@ -100,6 +105,12 @@
                                         <useTags>true</useTags>
                                         <useSpringBoot3>true</useSpringBoot3>
                                         <dateLibrary>java8</dateLibrary>
+                                        <generatedConstructorWithRequiredArgs>false</generatedConstructorWithRequiredArgs>
+                                        <additionalModelTypeAnnotations>
+                                            @lombok.experimental.SuperBuilder
+                                            @lombok.NoArgsConstructor
+                                            @lombok.AllArgsConstructor
+                                        </additionalModelTypeAnnotations>
                                     </configOptions>
                                 </configuration>
                             </execution>