diff --git a/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/Operator.java b/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/Operator.java
index 8a4b6850ac..12437155e9 100644
--- a/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/Operator.java
+++ b/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/Operator.java
@@ -76,7 +76,11 @@ public Operator(KubernetesClient kubernetesClient, ConfigurationService configur
         .ifPresent(c -> leaderElectionManager.init(c, this.kubernetesClient));
   }
 
-  /** Adds a shutdown hook that automatically calls {@link #stop()} when the app shuts down. */
+  /**
+   * Adds a shutdown hook that automatically calls {@link #stop()} when the app shuts down.
+   *
+   * @deprecated This feature should not be used anymore
+   */
   @Deprecated(forRemoval = true)
   public void installShutdownHook() {
     if (!leaderElectionManager.isLeaderElectionEnabled()) {
diff --git a/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/config/ConfigurationService.java b/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/config/ConfigurationService.java
index 45d7162184..1b356ea60d 100644
--- a/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/config/ConfigurationService.java
+++ b/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/config/ConfigurationService.java
@@ -195,6 +195,7 @@ default Optional<InformerStoppedHandler> getInformerStoppedHandler() {
     });
   }
 
+  @SuppressWarnings("rawtypes")
   default ManagedWorkflowFactory getWorkflowFactory() {
     return ManagedWorkflowFactory.DEFAULT;
   }
diff --git a/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/dependent/workflow/DefaultWorkflow.java b/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/dependent/workflow/DefaultWorkflow.java
index a151ff0947..3a5291c8b8 100644
--- a/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/dependent/workflow/DefaultWorkflow.java
+++ b/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/dependent/workflow/DefaultWorkflow.java
@@ -6,8 +6,6 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import java.util.function.Function;
-import java.util.stream.Collectors;
 
 import io.fabric8.kubernetes.api.model.HasMetadata;
 import io.javaoperatorsdk.operator.api.reconciler.Context;
@@ -65,21 +63,24 @@ protected DefaultWorkflow(Map<String, DependentResourceNode> dependentResourceNo
   }
 
   @SuppressWarnings("unchecked")
-  private Map<String, DependentResourceNode> toMap(
-      Set<DependentResourceNode> dependentResourceNodes) {
-    return dependentResourceNodes.stream()
-        .peek(drn -> {
-          // add cycle detection?
-          if (drn.getDependsOn().isEmpty()) {
-            topLevelResources.add(drn);
-          } else {
-            for (DependentResourceNode dependsOn : (List<DependentResourceNode>) drn
-                .getDependsOn()) {
-              bottomLevelResource.remove(dependsOn);
-            }
-          }
-        })
-        .collect(Collectors.toMap(DependentResourceNode::getName, Function.identity()));
+  private Map<String, DependentResourceNode> toMap(Set<DependentResourceNode> nodes) {
+    if (nodes == null || nodes.isEmpty()) {
+      return Collections.emptyMap();
+    }
+
+    final var map = new HashMap<String, DependentResourceNode>(nodes.size());
+    for (DependentResourceNode node : nodes) {
+      // add cycle detection?
+      if (node.getDependsOn().isEmpty()) {
+        topLevelResources.add(node);
+      } else {
+        for (DependentResourceNode dependsOn : (List<DependentResourceNode>) node.getDependsOn()) {
+          bottomLevelResource.remove(dependsOn);
+        }
+      }
+      map.put(node.getName(), node);
+    }
+    return map;
   }
 
   @Override
diff --git a/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/source/informer/InformerManager.java b/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/source/informer/InformerManager.java
index 94788e6706..34f89dd68b 100644
--- a/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/source/informer/InformerManager.java
+++ b/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/source/informer/InformerManager.java
@@ -1,6 +1,11 @@
 package io.javaoperatorsdk.operator.processing.event.source.informer;
 
-import java.util.*;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.function.Function;
 import java.util.function.Predicate;
@@ -55,8 +60,6 @@ void initSources(MixedOperation<T, KubernetesResourceList<T>, Resource<T>> clien
     this.eventHandler = eventHandler;
 
     final var targetNamespaces = configuration.getEffectiveNamespaces();
-    final var labelSelector = configuration.getLabelSelector();
-
     if (ResourceConfiguration.allNamespacesWatched(targetNamespaces)) {
       var source = createEventSourceForNamespace(WATCH_ALL_NAMESPACES);
       log.debug("Registered {} -> {} for any namespace", this, source);
diff --git a/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/source/informer/InformerWrapper.java b/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/source/informer/InformerWrapper.java
index ccb1d268ca..a872e9daa3 100644
--- a/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/source/informer/InformerWrapper.java
+++ b/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/source/informer/InformerWrapper.java
@@ -86,7 +86,7 @@ public void start() throws OperatorException {
           log.warn("Informer startup error. Will periodically retry. Informer: {}", informer, e);
         }
       } catch (InterruptedException e) {
-        Thread.currentThread().interrupt();
+        thread.interrupt();
         throw new IllegalStateException(e);
       } finally {
         // restore original name
diff --git a/operator-framework/src/test/java/io/javaoperatorsdk/operator/config/BaseConfigurationServiceTest.java b/operator-framework/src/test/java/io/javaoperatorsdk/operator/config/BaseConfigurationServiceTest.java
index 22af954661..339d2a02b4 100644
--- a/operator-framework/src/test/java/io/javaoperatorsdk/operator/config/BaseConfigurationServiceTest.java
+++ b/operator-framework/src/test/java/io/javaoperatorsdk/operator/config/BaseConfigurationServiceTest.java
@@ -126,8 +126,8 @@ void getDependentResources() {
 
   @Test
   void missingAnnotationThrowsException() {
-    Assertions.assertThrows(OperatorException.class,
-        () -> configFor(new MissingAnnotationReconciler()));
+    final var reconciler = new MissingAnnotationReconciler();
+    Assertions.assertThrows(OperatorException.class, () -> configFor(reconciler));
   }
 
   @SuppressWarnings("rawtypes")
@@ -145,7 +145,8 @@ private Optional<DependentResourceSpec> findByNameOptional(
 
   @Test
   void tryingToAddDuplicatedDependentsWithoutNameShouldFail() {
-    assertThrows(IllegalArgumentException.class, () -> configFor(new DuplicatedDepReconciler()));
+    final var reconciler = new DuplicatedDepReconciler();
+    assertThrows(IllegalArgumentException.class, () -> configFor(reconciler));
   }
 
   @Test
@@ -179,8 +180,7 @@ void checkDefaultRateAndRetryConfigurations() {
 
   @Test
   void configuringRateAndRetryViaAnnotationsShouldWork() {
-    var config =
-        configFor(new ConfigurableRateLimitAndRetryReconciler());
+    var config = configFor(new ConfigurableRateLimitAndRetryReconciler());
     final var retry = config.getRetry();
     final var testRetry = assertInstanceOf(TestRetry.class, retry);
     assertEquals(12, testRetry.getValue());