diff --git a/src/main/java/dev/openfeature/sdk/OpenFeatureAPI.java b/src/main/java/dev/openfeature/sdk/OpenFeatureAPI.java
index 66d40736f..6d0d8feb4 100644
--- a/src/main/java/dev/openfeature/sdk/OpenFeatureAPI.java
+++ b/src/main/java/dev/openfeature/sdk/OpenFeatureAPI.java
@@ -5,9 +5,12 @@
 import dev.openfeature.sdk.internal.AutoCloseableReentrantReadWriteLock;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 import java.util.Optional;
 import java.util.Set;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Consumer;
 import lombok.extern.slf4j.Slf4j;
 
@@ -21,14 +24,14 @@
 public class OpenFeatureAPI implements EventBus<OpenFeatureAPI> {
     // package-private multi-read/single-write lock
     static AutoCloseableReentrantReadWriteLock lock = new AutoCloseableReentrantReadWriteLock();
-    private final List<Hook> apiHooks;
+    private final ConcurrentLinkedQueue<Hook> apiHooks;
     private ProviderRepository providerRepository;
     private EventSupport eventSupport;
-    private EvaluationContext evaluationContext;
+    private final AtomicReference<EvaluationContext> evaluationContext = new AtomicReference<>();
     private TransactionContextPropagator transactionContextPropagator;
 
     protected OpenFeatureAPI() {
-        apiHooks = new ArrayList<>();
+        apiHooks = new ConcurrentLinkedQueue<>();
         providerRepository = new ProviderRepository(this);
         eventSupport = new EventSupport();
         transactionContextPropagator = new NoOpTransactionContextPropagator();
@@ -115,9 +118,7 @@ public Client getClient(String domain, String version) {
      * @return api instance
      */
     public OpenFeatureAPI setEvaluationContext(EvaluationContext evaluationContext) {
-        try (AutoCloseableLock __ = lock.writeLockAutoCloseable()) {
-            this.evaluationContext = evaluationContext;
-        }
+        this.evaluationContext.set(evaluationContext);
         return this;
     }
 
@@ -127,16 +128,14 @@ public OpenFeatureAPI setEvaluationContext(EvaluationContext evaluationContext)
      * @return evaluation context
      */
     public EvaluationContext getEvaluationContext() {
-        try (AutoCloseableLock __ = lock.readLockAutoCloseable()) {
-            return this.evaluationContext;
-        }
+        return evaluationContext.get();
     }
 
     /**
      * Return the transaction context propagator.
      */
     public TransactionContextPropagator getTransactionContextPropagator() {
-        try (AutoCloseableLock __ = lock.readLockAutoCloseable()) {
+        try (AutoCloseableLock ignored = lock.readLockAutoCloseable()) {
             return this.transactionContextPropagator;
         }
     }
@@ -150,7 +149,7 @@ public void setTransactionContextPropagator(TransactionContextPropagator transac
         if (transactionContextPropagator == null) {
             throw new IllegalArgumentException("Transaction context propagator cannot be null");
         }
-        try (AutoCloseableLock __ = lock.writeLockAutoCloseable()) {
+        try (AutoCloseableLock ignored = lock.writeLockAutoCloseable()) {
             this.transactionContextPropagator = transactionContextPropagator;
         }
     }
@@ -176,7 +175,7 @@ public void setTransactionContext(EvaluationContext evaluationContext) {
      * Set the default provider.
      */
     public void setProvider(FeatureProvider provider) {
-        try (AutoCloseableLock __ = lock.writeLockAutoCloseable()) {
+        try (AutoCloseableLock ignored = lock.writeLockAutoCloseable()) {
             providerRepository.setProvider(
                     provider,
                     this::attachEventProvider,
@@ -194,7 +193,7 @@ public void setProvider(FeatureProvider provider) {
      * @param provider The provider to set.
      */
     public void setProvider(String domain, FeatureProvider provider) {
-        try (AutoCloseableLock __ = lock.writeLockAutoCloseable()) {
+        try (AutoCloseableLock ignored = lock.writeLockAutoCloseable()) {
             providerRepository.setProvider(
                     domain,
                     provider,
@@ -216,7 +215,7 @@ public void setProvider(String domain, FeatureProvider provider) {
      * @throws OpenFeatureError if the provider fails during initialization.
      */
     public void setProviderAndWait(FeatureProvider provider) throws OpenFeatureError {
-        try (AutoCloseableLock __ = lock.writeLockAutoCloseable()) {
+        try (AutoCloseableLock ignored = lock.writeLockAutoCloseable()) {
             providerRepository.setProvider(
                     provider,
                     this::attachEventProvider,
@@ -238,7 +237,7 @@ public void setProviderAndWait(FeatureProvider provider) throws OpenFeatureError
      * @throws OpenFeatureError if the provider fails during initialization.
      */
     public void setProviderAndWait(String domain, FeatureProvider provider) throws OpenFeatureError {
-        try (AutoCloseableLock __ = lock.writeLockAutoCloseable()) {
+        try (AutoCloseableLock ignored = lock.writeLockAutoCloseable()) {
             providerRepository.setProvider(
                     domain,
                     provider,
@@ -252,9 +251,7 @@ public void setProviderAndWait(String domain, FeatureProvider provider) throws O
 
     private void attachEventProvider(FeatureProvider provider) {
         if (provider instanceof EventProvider) {
-            ((EventProvider) provider).attach((p, event, details) -> {
-                runHandlersForProvider(p, event, details);
-            });
+            ((EventProvider) provider).attach(this::runHandlersForProvider);
         }
     }
 
@@ -307,9 +304,7 @@ public FeatureProvider getProvider(String domain) {
      * @param hooks The hook to add.
      */
     public void addHooks(Hook... hooks) {
-        try (AutoCloseableLock __ = lock.writeLockAutoCloseable()) {
-            this.apiHooks.addAll(Arrays.asList(hooks));
-        }
+        this.apiHooks.addAll(Arrays.asList(hooks));
     }
 
     /**
@@ -318,18 +313,23 @@ public void addHooks(Hook... hooks) {
      * @return A list of {@link Hook}s.
      */
     public List<Hook> getHooks() {
-        try (AutoCloseableLock __ = lock.readLockAutoCloseable()) {
-            return this.apiHooks;
-        }
+        return new ArrayList<>(this.apiHooks);
+    }
+
+    /**
+     * Returns a reference to the collection of {@link Hook}s.
+     *
+     * @return The collection of {@link Hook}s.
+     */
+    Collection<Hook> getMutableHooks() {
+        return this.apiHooks;
     }
 
     /**
      * Removes all hooks.
      */
     public void clearHooks() {
-        try (AutoCloseableLock __ = lock.writeLockAutoCloseable()) {
-            this.apiHooks.clear();
-        }
+        this.apiHooks.clear();
     }
 
     /**
@@ -339,7 +339,7 @@ public void clearHooks() {
      * Once shut down is complete, API is reset and ready to use again.
      */
     public void shutdown() {
-        try (AutoCloseableLock __ = lock.writeLockAutoCloseable()) {
+        try (AutoCloseableLock ignored = lock.writeLockAutoCloseable()) {
             providerRepository.shutdown();
             eventSupport.shutdown();
 
@@ -385,7 +385,7 @@ public OpenFeatureAPI onProviderError(Consumer<EventDetails> handler) {
      */
     @Override
     public OpenFeatureAPI on(ProviderEvent event, Consumer<EventDetails> handler) {
-        try (AutoCloseableLock __ = lock.writeLockAutoCloseable()) {
+        try (AutoCloseableLock ignored = lock.writeLockAutoCloseable()) {
             this.eventSupport.addGlobalHandler(event, handler);
             return this;
         }
@@ -396,18 +396,20 @@ public OpenFeatureAPI on(ProviderEvent event, Consumer<EventDetails> handler) {
      */
     @Override
     public OpenFeatureAPI removeHandler(ProviderEvent event, Consumer<EventDetails> handler) {
-        this.eventSupport.removeGlobalHandler(event, handler);
+        try (AutoCloseableLock ignored = lock.writeLockAutoCloseable()) {
+            this.eventSupport.removeGlobalHandler(event, handler);
+        }
         return this;
     }
 
     void removeHandler(String domain, ProviderEvent event, Consumer<EventDetails> handler) {
-        try (AutoCloseableLock __ = lock.writeLockAutoCloseable()) {
+        try (AutoCloseableLock ignored = lock.writeLockAutoCloseable()) {
             eventSupport.removeClientHandler(domain, event, handler);
         }
     }
 
     void addHandler(String domain, ProviderEvent event, Consumer<EventDetails> handler) {
-        try (AutoCloseableLock __ = lock.writeLockAutoCloseable()) {
+        try (AutoCloseableLock ignored = lock.writeLockAutoCloseable()) {
             // if the provider is in the state associated with event, run immediately
             if (Optional.ofNullable(this.providerRepository.getProviderState(domain))
                     .orElse(ProviderState.READY)
@@ -431,32 +433,28 @@ FeatureProviderStateManager getFeatureProviderStateManager(String domain) {
      * @param details  the event details
      */
     private void runHandlersForProvider(FeatureProvider provider, ProviderEvent event, ProviderEventDetails details) {
-        try (AutoCloseableLock __ = lock.readLockAutoCloseable()) {
+        try (AutoCloseableLock ignored = lock.readLockAutoCloseable()) {
 
             List<String> domainsForProvider = providerRepository.getDomainsForProvider(provider);
 
             final String providerName = Optional.ofNullable(provider.getMetadata())
-                    .map(metadata -> metadata.getName())
+                    .map(Metadata::getName)
                     .orElse(null);
 
             // run the global handlers
             eventSupport.runGlobalHandlers(event, EventDetails.fromProviderEventDetails(details, providerName));
 
             // run the handlers associated with domains for this provider
-            domainsForProvider.forEach(domain -> {
-                eventSupport.runClientHandlers(
-                        domain, event, EventDetails.fromProviderEventDetails(details, providerName, domain));
-            });
+            domainsForProvider.forEach(domain -> eventSupport.runClientHandlers(
+                    domain, event, EventDetails.fromProviderEventDetails(details, providerName, domain)));
 
             if (providerRepository.isDefaultProvider(provider)) {
                 // run handlers for clients that have no bound providers (since this is the default)
                 Set<String> allDomainNames = eventSupport.getAllDomainNames();
                 Set<String> boundDomains = providerRepository.getAllBoundDomains();
                 allDomainNames.removeAll(boundDomains);
-                allDomainNames.forEach(domain -> {
-                    eventSupport.runClientHandlers(
-                            domain, event, EventDetails.fromProviderEventDetails(details, providerName, domain));
-                });
+                allDomainNames.forEach(domain -> eventSupport.runClientHandlers(
+                        domain, event, EventDetails.fromProviderEventDetails(details, providerName, domain)));
             }
         }
     }
diff --git a/src/main/java/dev/openfeature/sdk/OpenFeatureClient.java b/src/main/java/dev/openfeature/sdk/OpenFeatureClient.java
index e68d28f79..b5522b66a 100644
--- a/src/main/java/dev/openfeature/sdk/OpenFeatureClient.java
+++ b/src/main/java/dev/openfeature/sdk/OpenFeatureClient.java
@@ -5,9 +5,8 @@
 import dev.openfeature.sdk.exceptions.GeneralError;
 import dev.openfeature.sdk.exceptions.OpenFeatureError;
 import dev.openfeature.sdk.exceptions.ProviderNotReadyError;
-import dev.openfeature.sdk.internal.AutoCloseableLock;
-import dev.openfeature.sdk.internal.AutoCloseableReentrantReadWriteLock;
 import dev.openfeature.sdk.internal.ObjectUtils;
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -15,6 +14,8 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Consumer;
 import lombok.Getter;
 import lombok.extern.slf4j.Slf4j;
@@ -46,11 +47,9 @@ public class OpenFeatureClient implements Client {
     @Getter
     private final String version;
 
-    private final List<Hook> clientHooks;
+    private final ConcurrentLinkedQueue<Hook> clientHooks;
     private final HookSupport hookSupport;
-    AutoCloseableReentrantReadWriteLock hooksLock = new AutoCloseableReentrantReadWriteLock();
-    AutoCloseableReentrantReadWriteLock contextLock = new AutoCloseableReentrantReadWriteLock();
-    private EvaluationContext evaluationContext;
+    private final AtomicReference<EvaluationContext> evaluationContext = new AtomicReference<>();
 
     /**
      * Deprecated public constructor. Use OpenFeature.API.getClient() instead.
@@ -68,7 +67,7 @@ public OpenFeatureClient(OpenFeatureAPI openFeatureAPI, String domain, String ve
         this.openfeatureApi = openFeatureAPI;
         this.domain = domain;
         this.version = version;
-        this.clientHooks = new ArrayList<>();
+        this.clientHooks = new ConcurrentLinkedQueue<>();
         this.hookSupport = new HookSupport();
     }
 
@@ -125,9 +124,7 @@ public void track(String trackingEventName, EvaluationContext context, TrackingE
      */
     @Override
     public OpenFeatureClient addHooks(Hook... hooks) {
-        try (AutoCloseableLock __ = this.hooksLock.writeLockAutoCloseable()) {
-            this.clientHooks.addAll(Arrays.asList(hooks));
-        }
+        this.clientHooks.addAll(Arrays.asList(hooks));
         return this;
     }
 
@@ -136,9 +133,7 @@ public OpenFeatureClient addHooks(Hook... hooks) {
      */
     @Override
     public List<Hook> getHooks() {
-        try (AutoCloseableLock __ = this.hooksLock.readLockAutoCloseable()) {
-            return this.clientHooks;
-        }
+        return new ArrayList<>(this.clientHooks);
     }
 
     /**
@@ -146,9 +141,7 @@ public List<Hook> getHooks() {
      */
     @Override
     public OpenFeatureClient setEvaluationContext(EvaluationContext evaluationContext) {
-        try (AutoCloseableLock __ = contextLock.writeLockAutoCloseable()) {
-            this.evaluationContext = evaluationContext;
-        }
+        this.evaluationContext.set(evaluationContext);
         return this;
     }
 
@@ -157,32 +150,33 @@ public OpenFeatureClient setEvaluationContext(EvaluationContext evaluationContex
      */
     @Override
     public EvaluationContext getEvaluationContext() {
-        try (AutoCloseableLock __ = contextLock.readLockAutoCloseable()) {
-            return this.evaluationContext;
-        }
+        return this.evaluationContext.get();
     }
 
+    @SuppressFBWarnings(
+            value = {"REC_CATCH_EXCEPTION"},
+            justification = "We don't want to allow any exception to reach the user. "
+                    + "Instead, we return an evaluation result with the appropriate error code.")
     private <T> FlagEvaluationDetails<T> evaluateFlag(
             FlagValueType type, String key, T defaultValue, EvaluationContext ctx, FlagEvaluationOptions options) {
-        FlagEvaluationOptions flagOptions = ObjectUtils.defaultIfNull(
+        var flagOptions = ObjectUtils.defaultIfNull(
                 options, () -> FlagEvaluationOptions.builder().build());
-        Map<String, Object> hints = Collections.unmodifiableMap(flagOptions.getHookHints());
+        var hints = Collections.unmodifiableMap(flagOptions.getHookHints());
 
         FlagEvaluationDetails<T> details = null;
         List<Hook> mergedHooks = null;
         HookContext<T> afterHookContext = null;
-        FeatureProvider provider;
 
         try {
-            FeatureProviderStateManager stateManager = openfeatureApi.getFeatureProviderStateManager(this.domain);
+            var stateManager = openfeatureApi.getFeatureProviderStateManager(this.domain);
             // provider must be accessed once to maintain a consistent reference
-            provider = stateManager.getProvider();
-            ProviderState state = stateManager.getState();
+            var provider = stateManager.getProvider();
+            var state = stateManager.getState();
 
             mergedHooks = ObjectUtils.merge(
-                    provider.getProviderHooks(), flagOptions.getHooks(), clientHooks, openfeatureApi.getHooks());
+                    provider.getProviderHooks(), flagOptions.getHooks(), clientHooks, openfeatureApi.getMutableHooks());
 
-            EvaluationContext mergedCtx = hookSupport.beforeHooks(
+            var mergedCtx = hookSupport.beforeHooks(
                     type,
                     HookContext.from(
                             key,
@@ -205,12 +199,12 @@ private <T> FlagEvaluationDetails<T> evaluateFlag(
                 throw new FatalError("Provider is in an irrecoverable error state");
             }
 
-            ProviderEvaluation<T> providerEval =
+            var providerEval =
                     (ProviderEvaluation<T>) createProviderEvaluation(type, key, defaultValue, provider, mergedCtx);
 
             details = FlagEvaluationDetails.from(providerEval, key);
             if (details.getErrorCode() != null) {
-                OpenFeatureError error =
+                var error =
                         ExceptionUtils.instantiateErrorByErrorCode(details.getErrorCode(), details.getErrorMessage());
                 enrichDetailsWithErrorDefaults(defaultValue, details);
                 hookSupport.errorHooks(type, afterHookContext, error, mergedHooks, hints);
@@ -264,7 +258,7 @@ private void invokeTrack(String trackingEventName, EvaluationContext context, Tr
      */
     private EvaluationContext mergeEvaluationContext(EvaluationContext invocationContext) {
         final EvaluationContext apiContext = openfeatureApi.getEvaluationContext();
-        final EvaluationContext clientContext = this.getEvaluationContext();
+        final EvaluationContext clientContext = evaluationContext.get();
         final EvaluationContext transactionContext = openfeatureApi.getTransactionContext();
         return mergeContextMaps(apiContext, transactionContext, clientContext, invocationContext);
     }
diff --git a/src/main/java/dev/openfeature/sdk/internal/ObjectUtils.java b/src/main/java/dev/openfeature/sdk/internal/ObjectUtils.java
index b367820c2..86a9ddd70 100644
--- a/src/main/java/dev/openfeature/sdk/internal/ObjectUtils.java
+++ b/src/main/java/dev/openfeature/sdk/internal/ObjectUtils.java
@@ -1,6 +1,7 @@
 package dev.openfeature.sdk.internal;
 
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 import java.util.function.Supplier;
@@ -64,9 +65,9 @@ public static <T> T defaultIfNull(T source, Supplier<T> defaultValue) {
      * @return resulting object
      */
     @SafeVarargs
-    public static <T> List<T> merge(List<T>... sources) {
+    public static <T> List<T> merge(Collection<T>... sources) {
         List<T> merged = new ArrayList<>();
-        for (List<T> source : sources) {
+        for (Collection<T> source : sources) {
             merged.addAll(source);
         }
         return merged;
diff --git a/src/test/java/dev/openfeature/sdk/LockingSingeltonTest.java b/src/test/java/dev/openfeature/sdk/LockingSingeltonTest.java
index ad86f4bc3..ae3246cae 100644
--- a/src/test/java/dev/openfeature/sdk/LockingSingeltonTest.java
+++ b/src/test/java/dev/openfeature/sdk/LockingSingeltonTest.java
@@ -20,7 +20,6 @@ class LockingSingeltonTest {
     private static OpenFeatureAPI api;
     private OpenFeatureClient client;
     private AutoCloseableReentrantReadWriteLock apiLock;
-    private AutoCloseableReentrantReadWriteLock clientContextLock;
     private AutoCloseableReentrantReadWriteLock clientHooksLock;
 
     @BeforeAll
@@ -36,10 +35,7 @@ void beforeEach() {
         apiLock = setupLock(apiLock, mockInnerReadLock(), mockInnerWriteLock());
         OpenFeatureAPI.lock = apiLock;
 
-        clientContextLock = setupLock(clientContextLock, mockInnerReadLock(), mockInnerWriteLock());
         clientHooksLock = setupLock(clientHooksLock, mockInnerReadLock(), mockInnerWriteLock());
-        client.contextLock = clientContextLock;
-        client.hooksLock = clientHooksLock;
     }
 
     @Nested
@@ -137,50 +133,6 @@ void onProviderErrorProviderReadyShouldApiWriteLockAndUnlock() {
         }
     }
 
-    @Test
-    void addHooksShouldWriteLockAndUnlock() {
-        client.addHooks(new Hook() {});
-        verify(clientHooksLock.writeLock()).lock();
-        verify(clientHooksLock.writeLock()).unlock();
-
-        api.addHooks(new Hook() {});
-        verify(apiLock.writeLock()).lock();
-        verify(apiLock.writeLock()).unlock();
-    }
-
-    @Test
-    void getHooksShouldReadLockAndUnlock() {
-        client.getHooks();
-        verify(clientHooksLock.readLock()).lock();
-        verify(clientHooksLock.readLock()).unlock();
-
-        api.getHooks();
-        verify(apiLock.readLock()).lock();
-        verify(apiLock.readLock()).unlock();
-    }
-
-    @Test
-    void setContextShouldWriteLockAndUnlock() {
-        client.setEvaluationContext(new ImmutableContext());
-        verify(clientContextLock.writeLock()).lock();
-        verify(clientContextLock.writeLock()).unlock();
-
-        api.setEvaluationContext(new ImmutableContext());
-        verify(apiLock.writeLock()).lock();
-        verify(apiLock.writeLock()).unlock();
-    }
-
-    @Test
-    void getContextShouldReadLockAndUnlock() {
-        client.getEvaluationContext();
-        verify(clientContextLock.readLock()).lock();
-        verify(clientContextLock.readLock()).unlock();
-
-        api.getEvaluationContext();
-        verify(apiLock.readLock()).lock();
-        verify(apiLock.readLock()).unlock();
-    }
-
     @Test
     void setTransactionalContextPropagatorShouldWriteLockAndUnlock() {
         api.setTransactionContextPropagator(new NoOpTransactionContextPropagator());
@@ -195,13 +147,6 @@ void getTransactionalContextPropagatorShouldReadLockAndUnlock() {
         verify(apiLock.readLock()).unlock();
     }
 
-    @Test
-    void clearHooksShouldWriteLockAndUnlock() {
-        api.clearHooks();
-        verify(apiLock.writeLock()).lock();
-        verify(apiLock.writeLock()).unlock();
-    }
-
     private static ReentrantReadWriteLock.ReadLock mockInnerReadLock() {
         ReentrantReadWriteLock.ReadLock readLockMock = mock(ReentrantReadWriteLock.ReadLock.class);
         doNothing().when(readLockMock).lock();