diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/WhisperServerService.java b/service/src/main/java/org/whispersystems/textsecuregcm/WhisperServerService.java
index f5d497329..60c2041fb 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/WhisperServerService.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/WhisperServerService.java
@@ -43,6 +43,7 @@ import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.SynchronousQueue;
 import java.util.concurrent.ThreadPoolExecutor;
 import java.util.stream.Stream;
 import javax.servlet.DispatcherType;
@@ -463,7 +464,7 @@ public class WhisperServerService extends Application<WhisperServerConfiguration
         .scheduledExecutorService(name(getClass(), "storageServiceRetry-%d")).threads(1).build();
     ScheduledExecutorService hcaptchaRetryExecutor = environment.lifecycle()
         .scheduledExecutorService(name(getClass(), "hCaptchaRetry-%d")).threads(1).build();
-    ScheduledExecutorService remoteStorageExecutor = environment.lifecycle()
+    ScheduledExecutorService remoteStorageRetryExecutor = environment.lifecycle()
         .scheduledExecutorService(name(getClass(), "remoteStorageRetry-%d")).threads(1).build();
     ScheduledExecutorService registrationIdentityTokenRefreshExecutor = environment.lifecycle()
         .scheduledExecutorService(name(getClass(), "registrationIdentityTokenRefresh-%d")).threads(1).build();
@@ -512,6 +513,23 @@ public class WhisperServerService extends Application<WhisperServerConfiguration
         .minThreads(8)
         .maxThreads(8)
         .build();
+    // unbounded executor (same as cachedThreadPool)
+    ExecutorService hcaptchaHttpExecutor = environment.lifecycle()
+        .executorService(name(getClass(), "hcaptcha-%d"))
+        .minThreads(0)
+        .maxThreads(Integer.MAX_VALUE)
+        .workQueue(new SynchronousQueue<>())
+        .keepAliveTime(io.dropwizard.util.Duration.seconds(60L))
+        .build();
+    // unbounded executor (same as cachedThreadPool)
+    ExecutorService remoteStorageHttpExecutor = environment.lifecycle()
+        .executorService(name(getClass(), "remoteStorage-%d"))
+        .minThreads(0)
+        .maxThreads(Integer.MAX_VALUE)
+        .workQueue(new SynchronousQueue<>())
+        .keepAliveTime(io.dropwizard.util.Duration.seconds(60L))
+        .build();
+
     ScheduledExecutorService subscriptionProcessorRetryExecutor = environment.lifecycle()
         .scheduledExecutorService(name(getClass(), "subscriptionProcessorRetry-%d")).threads(1).build();
 
@@ -613,7 +631,7 @@ public class WhisperServerService extends Application<WhisperServerConfiguration
         config.getMessageByteLimitCardinalityEstimator().period());
 
     HCaptchaClient hCaptchaClient = config.getHCaptchaConfiguration()
-        .build(hcaptchaRetryExecutor, dynamicConfigurationManager);
+        .build(hcaptchaRetryExecutor, hcaptchaHttpExecutor, dynamicConfigurationManager);
     HttpClient shortCodeRetrieverHttpClient = HttpClient.newBuilder().version(HttpClient.Version.HTTP_2)
         .connectTimeout(Duration.ofSeconds(10)).build();
     ShortCodeExpander shortCodeRetriever = new ShortCodeExpander(shortCodeRetrieverHttpClient, config.getShortCodeRetrieverConfiguration().baseUrl());
@@ -697,13 +715,17 @@ public class WhisperServerService extends Application<WhisperServerConfiguration
         dynamoDbAsyncClient,
         config.getDynamoDbTables().getBackups().getTableName(),
         clock);
+    final Cdn3RemoteStorageManager cdn3RemoteStorageManager = new Cdn3RemoteStorageManager(
+        remoteStorageHttpExecutor,
+        remoteStorageRetryExecutor,
+        config.getCdn3StorageManagerConfiguration());
     BackupManager backupManager = new BackupManager(
         backupsDb,
         backupsGenericZkSecretParams,
         rateLimiters,
         tusAttachmentGenerator,
         cdn3BackupCredentialGenerator,
-        new Cdn3RemoteStorageManager(remoteStorageExecutor, config.getCdn3StorageManagerConfiguration()),
+        cdn3RemoteStorageManager,
         clock);
 
     final DynamicConfigTurnRouter configTurnRouter = new DynamicConfigTurnRouter(dynamicConfigurationManager);
diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/backup/Cdn3RemoteStorageManager.java b/service/src/main/java/org/whispersystems/textsecuregcm/backup/Cdn3RemoteStorageManager.java
index 2ccdb1726..67350d2da 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/backup/Cdn3RemoteStorageManager.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/backup/Cdn3RemoteStorageManager.java
@@ -18,6 +18,7 @@ import java.util.Map;
 import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.CompletionStage;
+import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledExecutorService;
 import javax.annotation.Nullable;
@@ -55,6 +56,7 @@ public class Cdn3RemoteStorageManager implements RemoteStorageManager {
   private static final String STATUS_TAG_NAME = "status";
 
   public Cdn3RemoteStorageManager(
+      final ExecutorService httpExecutor,
       final ScheduledExecutorService retryExecutor,
       final Cdn3StorageManagerConfiguration configuration) {
 
@@ -67,7 +69,7 @@ public class Cdn3RemoteStorageManager implements RemoteStorageManager {
     this.storageManagerHttpClient = FaultTolerantHttpClient.newBuilder()
         .withName("cdn3-storage-manager")
         .withCircuitBreaker(configuration.circuitBreaker())
-        .withExecutor(Executors.newCachedThreadPool())
+        .withExecutor(httpExecutor)
         .withRetryExecutor(retryExecutor)
         .withRetry(configuration.retry())
         .withConnectTimeout(Duration.ofSeconds(10))
diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/captcha/HCaptchaClient.java b/service/src/main/java/org/whispersystems/textsecuregcm/captcha/HCaptchaClient.java
index b78fa60ad..b2582370c 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/captcha/HCaptchaClient.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/captcha/HCaptchaClient.java
@@ -60,6 +60,7 @@ public class HCaptchaClient implements CaptchaClient {
   public HCaptchaClient(
       final String apiKey,
       final ScheduledExecutorService retryExecutor,
+      final ExecutorService httpExecutor,
       final CircuitBreakerConfiguration circuitBreakerConfiguration,
       final RetryConfiguration retryConfiguration,
       final DynamicConfigurationManager<DynamicConfiguration> dynamicConfigurationManager) {
@@ -67,7 +68,7 @@ public class HCaptchaClient implements CaptchaClient {
         FaultTolerantHttpClient.newBuilder()
             .withName("hcaptcha")
             .withCircuitBreaker(circuitBreakerConfiguration)
-            .withExecutor(Executors.newCachedThreadPool())
+            .withExecutor(httpExecutor)
             .withRetryExecutor(retryExecutor)
             .withRetry(retryConfiguration)
             .withRetryOnException(ex -> ex instanceof IOException)
diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/configuration/HCaptchaClientFactory.java b/service/src/main/java/org/whispersystems/textsecuregcm/configuration/HCaptchaClientFactory.java
index 1e67f186c..5029e9cdc 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/configuration/HCaptchaClientFactory.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/configuration/HCaptchaClientFactory.java
@@ -10,11 +10,12 @@ import io.dropwizard.jackson.Discoverable;
 import org.whispersystems.textsecuregcm.captcha.HCaptchaClient;
 import org.whispersystems.textsecuregcm.configuration.dynamic.DynamicConfiguration;
 import org.whispersystems.textsecuregcm.storage.DynamicConfigurationManager;
+import java.util.concurrent.ExecutorService;
 import java.util.concurrent.ScheduledExecutorService;
 
 @JsonTypeInfo(use = JsonTypeInfo.Id.NAME, property = "type", defaultImpl = HCaptchaConfiguration.class)
 public interface HCaptchaClientFactory extends Discoverable {
 
-  HCaptchaClient build(ScheduledExecutorService retryExecutor,
+  HCaptchaClient build(ScheduledExecutorService retryExecutor, ExecutorService httpExecutor,
       DynamicConfigurationManager<DynamicConfiguration> dynamicConfigurationManager);
 }
diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/configuration/HCaptchaConfiguration.java b/service/src/main/java/org/whispersystems/textsecuregcm/configuration/HCaptchaConfiguration.java
index 0d401ef12..c2cf34b79 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/configuration/HCaptchaConfiguration.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/configuration/HCaptchaConfiguration.java
@@ -12,6 +12,7 @@ import org.whispersystems.textsecuregcm.captcha.HCaptchaClient;
 import org.whispersystems.textsecuregcm.configuration.dynamic.DynamicConfiguration;
 import org.whispersystems.textsecuregcm.configuration.secrets.SecretString;
 import org.whispersystems.textsecuregcm.storage.DynamicConfigurationManager;
+import java.util.concurrent.ExecutorService;
 import java.util.concurrent.ScheduledExecutorService;
 
 @JsonTypeName("default")
@@ -43,11 +44,14 @@ public class HCaptchaConfiguration implements HCaptchaClientFactory {
   }
 
   @Override
-  public HCaptchaClient build(final ScheduledExecutorService retryExecutor,
+  public HCaptchaClient build(
+      final ScheduledExecutorService retryExecutor,
+      final ExecutorService httpExecutor,
       final DynamicConfigurationManager<DynamicConfiguration> dynamicConfigurationManager) {
     return new HCaptchaClient(
         apiKey.value(),
         retryExecutor,
+        httpExecutor,
         circuitBreaker,
         retry,
         dynamicConfigurationManager);
diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/workers/CommandDependencies.java b/service/src/main/java/org/whispersystems/textsecuregcm/workers/CommandDependencies.java
index 4747e07a3..ed91149f4 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/workers/CommandDependencies.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/workers/CommandDependencies.java
@@ -15,6 +15,7 @@ import java.security.cert.CertificateException;
 import java.time.Clock;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.SynchronousQueue;
 import org.signal.libsignal.zkgroup.GenericServerSecretParams;
 import org.signal.libsignal.zkgroup.InvalidInputException;
 import org.whispersystems.textsecuregcm.WhisperServerConfiguration;
@@ -111,10 +112,14 @@ record CommandDependencies(
         .executorService(name(name, "accountLock-%d")).minThreads(8).maxThreads(8).build();
     ExecutorService clientPresenceExecutor = environment.lifecycle()
         .executorService(name(name, "clientPresence-%d")).minThreads(8).maxThreads(8).build();
+    ExecutorService remoteStorageHttpExecutor = environment.lifecycle()
+        .executorService(name(name, "remoteStorage-%d"))
+        .minThreads(0).maxThreads(Integer.MAX_VALUE).workQueue(new SynchronousQueue<>())
+        .keepAliveTime(io.dropwizard.util.Duration.seconds(60L)).build();
 
     ScheduledExecutorService secureValueRecoveryServiceRetryExecutor = environment.lifecycle()
         .scheduledExecutorService(name(name, "secureValueRecoveryServiceRetry-%d")).threads(1).build();
-    ScheduledExecutorService remoteStorageExecutor = environment.lifecycle()
+    ScheduledExecutorService remoteStorageRetryExecutor = environment.lifecycle()
         .scheduledExecutorService(name(name, "remoteStorageRetry-%d")).threads(1).build();
     ScheduledExecutorService storageServiceRetryExecutor = environment.lifecycle()
         .scheduledExecutorService(name(name, "storageServiceRetry-%d")).threads(1).build();
@@ -211,7 +216,10 @@ record CommandDependencies(
         rateLimiters,
         new TusAttachmentGenerator(configuration.getTus()),
         new Cdn3BackupCredentialGenerator(configuration.getTus()),
-        new Cdn3RemoteStorageManager(remoteStorageExecutor, configuration.getCdn3StorageManagerConfiguration()),
+        new Cdn3RemoteStorageManager(
+            remoteStorageHttpExecutor,
+            remoteStorageRetryExecutor,
+            configuration.getCdn3StorageManagerConfiguration()),
         clock);
 
     environment.lifecycle().manage(messagesCache);
diff --git a/service/src/test/java/org/whispersystems/textsecuregcm/backup/Cdn3RemoteStorageManagerTest.java b/service/src/test/java/org/whispersystems/textsecuregcm/backup/Cdn3RemoteStorageManagerTest.java
index 132138a62..7083714aa 100644
--- a/service/src/test/java/org/whispersystems/textsecuregcm/backup/Cdn3RemoteStorageManagerTest.java
+++ b/service/src/test/java/org/whispersystems/textsecuregcm/backup/Cdn3RemoteStorageManagerTest.java
@@ -51,6 +51,7 @@ public class Cdn3RemoteStorageManagerTest {
   @BeforeEach
   public void init() {
     remoteStorageManager = new Cdn3RemoteStorageManager(
+        Executors.newCachedThreadPool(),
         Executors.newSingleThreadScheduledExecutor(),
         new Cdn3StorageManagerConfiguration(
             wireMock.url("storage-manager/"),
diff --git a/service/src/test/java/org/whispersystems/textsecuregcm/configuration/StubHCaptchaClientFactory.java b/service/src/test/java/org/whispersystems/textsecuregcm/configuration/StubHCaptchaClientFactory.java
index d68f42b7d..21025ee11 100644
--- a/service/src/test/java/org/whispersystems/textsecuregcm/configuration/StubHCaptchaClientFactory.java
+++ b/service/src/test/java/org/whispersystems/textsecuregcm/configuration/StubHCaptchaClientFactory.java
@@ -8,6 +8,7 @@ package org.whispersystems.textsecuregcm.configuration;
 import com.fasterxml.jackson.annotation.JsonTypeName;
 import java.io.IOException;
 import java.util.Set;
+import java.util.concurrent.ExecutorService;
 import java.util.concurrent.ScheduledExecutorService;
 import org.whispersystems.textsecuregcm.captcha.Action;
 import org.whispersystems.textsecuregcm.captcha.AssessmentResult;
@@ -19,10 +20,11 @@ import org.whispersystems.textsecuregcm.storage.DynamicConfigurationManager;
 public class StubHCaptchaClientFactory implements HCaptchaClientFactory {
 
   @Override
-  public HCaptchaClient build(final ScheduledExecutorService retryExecutor,
+  public HCaptchaClient build(final ScheduledExecutorService retryExecutor, ExecutorService httpExecutor,
       final DynamicConfigurationManager<DynamicConfiguration> dynamicConfigurationManager) {
 
-    return new StubHCaptchaClient(retryExecutor, new CircuitBreakerConfiguration(), dynamicConfigurationManager);
+    return new StubHCaptchaClient(retryExecutor, httpExecutor, new CircuitBreakerConfiguration(),
+        dynamicConfigurationManager);
   }
 
   /**
@@ -30,10 +32,10 @@ public class StubHCaptchaClientFactory implements HCaptchaClientFactory {
    */
   private static class StubHCaptchaClient extends HCaptchaClient {
 
-    public StubHCaptchaClient(final ScheduledExecutorService retryExecutor,
+    public StubHCaptchaClient(final ScheduledExecutorService retryExecutor, ExecutorService httpExecutor,
         final CircuitBreakerConfiguration circuitBreakerConfiguration,
         final DynamicConfigurationManager<DynamicConfiguration> dynamicConfigurationManager) {
-      super(null, retryExecutor, circuitBreakerConfiguration, null, dynamicConfigurationManager);
+      super(null, retryExecutor, httpExecutor, circuitBreakerConfiguration, null, dynamicConfigurationManager);
     }
 
     @Override