diff --git a/common/dao-api/src/main/java/org/thingsboard/server/dao/timeseries/TimeseriesService.java b/common/dao-api/src/main/java/org/thingsboard/server/dao/timeseries/TimeseriesService.java
index 096a39bff6..c62898ab09 100644
--- a/common/dao-api/src/main/java/org/thingsboard/server/dao/timeseries/TimeseriesService.java
+++ b/common/dao-api/src/main/java/org/thingsboard/server/dao/timeseries/TimeseriesService.java
@@ -38,7 +38,7 @@ public interface TimeseriesService {
 
     ListenableFuture<List<TsKvEntry>> findAll(TenantId tenantId, EntityId entityId, List<ReadTsKvQuery> queries);
 
-    ListenableFuture<Optional<TsKvEntry>> findLatest(TenantId tenantId, EntityId entityId, String keys);
+    ListenableFuture<Optional<TsKvEntry>> findLatest(TenantId tenantId, EntityId entityId, String key);
 
     ListenableFuture<List<TsKvEntry>> findLatest(TenantId tenantId, EntityId entityId, Collection<String> keys);
 
diff --git a/rule-engine/rule-engine-components/src/main/java/org/thingsboard/rule/engine/metadata/CalculateDeltaNode.java b/rule-engine/rule-engine-components/src/main/java/org/thingsboard/rule/engine/metadata/CalculateDeltaNode.java
index 609888db84..88540ffe4a 100644
--- a/rule-engine/rule-engine-components/src/main/java/org/thingsboard/rule/engine/metadata/CalculateDeltaNode.java
+++ b/rule-engine/rule-engine-components/src/main/java/org/thingsboard/rule/engine/metadata/CalculateDeltaNode.java
@@ -37,7 +37,6 @@ import org.thingsboard.server.dao.timeseries.TimeseriesService;
 
 import java.math.BigDecimal;
 import java.math.RoundingMode;
-import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
@@ -129,8 +128,8 @@ public class CalculateDeltaNode implements TbNode {
     }
 
     private ListenableFuture<ValueWithTs> fetchLatestValueAsync(EntityId entityId) {
-        return Futures.transform(timeseriesService.findLatest(ctx.getTenantId(), entityId, Collections.singletonList(config.getInputValueKey())),
-                list -> extractValue(list.get(0))
+        return Futures.transform(timeseriesService.findLatest(ctx.getTenantId(), entityId, config.getInputValueKey()),
+                tsKvEntryOpt -> tsKvEntryOpt.map(this::extractValue).orElse(null)
                 , ctx.getDbCallbackExecutor());
     }
 
@@ -138,7 +137,7 @@ public class CalculateDeltaNode implements TbNode {
         List<TsKvEntry> tsKvEntries = timeseriesService.findLatestSync(
                 ctx.getTenantId(),
                 entityId,
-                Collections.singletonList(config.getInputValueKey()));
+                List.of(config.getInputValueKey()));
         return extractValue(tsKvEntries.get(0));
     }
 
@@ -161,36 +160,23 @@ public class CalculateDeltaNode implements TbNode {
         double result = 0.0;
         long ts = kvEntry.getTs();
         switch (kvEntry.getDataType()) {
-            case LONG:
-                result = kvEntry.getLongValue().get();
-                break;
-            case DOUBLE:
-                result = kvEntry.getDoubleValue().get();
-                break;
-            case STRING:
+            case LONG -> result = kvEntry.getLongValue().get();
+            case DOUBLE -> result = kvEntry.getDoubleValue().get();
+            case STRING -> {
                 try {
                     result = Double.parseDouble(kvEntry.getStrValue().get());
                 } catch (NumberFormatException e) {
                     throw new IllegalArgumentException("Calculation failed. Unable to parse value [" + kvEntry.getStrValue().get() + "]" +
                             " of telemetry [" + kvEntry.getKey() + "] to Double");
                 }
-                break;
-            case BOOLEAN:
-                throw new IllegalArgumentException("Calculation failed. Boolean values are not supported!");
-            case JSON:
-                throw new IllegalArgumentException("Calculation failed. JSON values are not supported!");
+            }
+            case BOOLEAN -> throw new IllegalArgumentException("Calculation failed. Boolean values are not supported!");
+            case JSON -> throw new IllegalArgumentException("Calculation failed. JSON values are not supported!");
         }
         return new ValueWithTs(ts, result);
     }
 
-    private static class ValueWithTs {
-        private final long ts;
-        private final double value;
-
-        private ValueWithTs(long ts, double value) {
-            this.ts = ts;
-            this.value = value;
-        }
+    private record ValueWithTs(long ts, double value) {
     }
 
 }
diff --git a/rule-engine/rule-engine-components/src/test/java/org/thingsboard/rule/engine/metadata/CalculateDeltaNodeTest.java b/rule-engine/rule-engine-components/src/test/java/org/thingsboard/rule/engine/metadata/CalculateDeltaNodeTest.java
index 707de1741f..188dd2e4ec 100644
--- a/rule-engine/rule-engine-components/src/test/java/org/thingsboard/rule/engine/metadata/CalculateDeltaNodeTest.java
+++ b/rule-engine/rule-engine-components/src/test/java/org/thingsboard/rule/engine/metadata/CalculateDeltaNodeTest.java
@@ -47,6 +47,7 @@ import org.thingsboard.server.common.msg.TbMsgMetaData;
 import org.thingsboard.server.dao.timeseries.TimeseriesService;
 
 import java.util.List;
+import java.util.Optional;
 import java.util.UUID;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
@@ -68,9 +69,9 @@ import static org.mockito.Mockito.when;
 @ExtendWith(MockitoExtension.class)
 public class CalculateDeltaNodeTest {
 
-    private static final DeviceId DUMMY_DEVICE_ORIGINATOR = new DeviceId(UUID.randomUUID());
-    private static final TenantId TENANT_ID = new TenantId(UUID.randomUUID());
-    private static final ListeningExecutor DB_EXECUTOR = new TestDbCallbackExecutor();
+    private final DeviceId DUMMY_DEVICE_ORIGINATOR = new DeviceId(UUID.fromString("2ba3ded4-882b-40cf-999a-89da9ccd58f9"));
+    private final TenantId TENANT_ID = new TenantId(UUID.fromString("3842e740-0d89-43a9-8d52-ae44023847ba"));
+    private final ListeningExecutor DB_EXECUTOR = new TestDbCallbackExecutor();
     @Mock
     private TbContext ctxMock;
     @Mock
@@ -435,8 +436,8 @@ public class CalculateDeltaNodeTest {
         when(ctxMock.getDbCallbackExecutor()).thenReturn(DB_EXECUTOR);
         when(ctxMock.getTenantId()).thenReturn(TENANT_ID);
         when(timeseriesServiceMock.findLatest(
-                eq(TENANT_ID), eq(DUMMY_DEVICE_ORIGINATOR), argThat(new ListMatcher<>(List.of(tsKvEntry.getKey())))
-        )).thenReturn(Futures.immediateFuture(List.of(tsKvEntry)));
+                eq(TENANT_ID), eq(DUMMY_DEVICE_ORIGINATOR), eq(tsKvEntry.getKey())
+        )).thenReturn(Futures.immediateFuture(Optional.of(tsKvEntry)));
     }
 
     @RequiredArgsConstructor