diff --git a/sdk/src/main/java/com/amplitude/experiment/DefaultExperimentClient.kt b/sdk/src/main/java/com/amplitude/experiment/DefaultExperimentClient.kt
index 54b8cd6..81935ea 100644
--- a/sdk/src/main/java/com/amplitude/experiment/DefaultExperimentClient.kt
+++ b/sdk/src/main/java/com/amplitude/experiment/DefaultExperimentClient.kt
@@ -4,7 +4,6 @@ import com.amplitude.experiment.evaluation.EvaluationEngineImpl
 import com.amplitude.experiment.evaluation.EvaluationFlag
 import com.amplitude.experiment.evaluation.json
 import com.amplitude.experiment.evaluation.topologicalSort
-import com.amplitude.experiment.storage.LoadStoreCache
 import com.amplitude.experiment.storage.Storage
 import com.amplitude.experiment.storage.getFlagStorage
 import com.amplitude.experiment.storage.getVariantStorage
@@ -59,23 +58,31 @@ internal class DefaultExperimentClient internal constructor(
     private var user: ExperimentUser? = null
     private val engine = EvaluationEngineImpl()
 
-    private val variants: LoadStoreCache<Variant> =
+    private val variants =
         getVariantStorage(
             this.apiKey,
             this.config.instanceName,
             storage,
         )
-    private val flags: LoadStoreCache<EvaluationFlag> =
+    private val flags =
         getFlagStorage(
             this.apiKey,
             this.config.instanceName,
             storage,
+            ::mergeInitialFlagsWithStorage,
         )
 
     init {
-        this.variants.load()
-        this.flags.load()
-        mergeInitialFlagsWithStorage()
+        executorService.execute {
+            synchronized(variants) {
+                this.variants.load()
+            }
+        }
+        executorService.execute {
+            synchronized(flags) {
+                this.flags.load()
+            }
+        }
     }
 
     private val backoffLock = Any()
diff --git a/sdk/src/main/java/com/amplitude/experiment/Experiment.kt b/sdk/src/main/java/com/amplitude/experiment/Experiment.kt
index 04d689f..3585e09 100644
--- a/sdk/src/main/java/com/amplitude/experiment/Experiment.kt
+++ b/sdk/src/main/java/com/amplitude/experiment/Experiment.kt
@@ -17,7 +17,7 @@ object Experiment {
                 isDaemon = true
             }
         }
-    internal val executorService = ScheduledThreadPoolExecutor(2, daemonThreadFactory)
+    internal val executorService = ScheduledThreadPoolExecutor(4, daemonThreadFactory)
 
     private val httpClient = OkHttpClient()
     private val instances = mutableMapOf<String, ExperimentClient>()
diff --git a/sdk/src/main/java/com/amplitude/experiment/storage/Cache.kt b/sdk/src/main/java/com/amplitude/experiment/storage/Cache.kt
index e4fa3b6..17993b7 100644
--- a/sdk/src/main/java/com/amplitude/experiment/storage/Cache.kt
+++ b/sdk/src/main/java/com/amplitude/experiment/storage/Cache.kt
@@ -13,14 +13,18 @@ internal class LoadStoreCache<V>(
     private val storage: Storage,
     private val decoder: ((value: String) -> V?),
     private val encoder: ((value: V) -> String),
+    private val onLoad: (() -> Unit)? = null,
 ) {
     private val cache: MutableMap<String, V> = mutableMapOf()
+    private var isLoaded = false
 
     fun get(key: String): V? {
+        if (!isLoaded) load()
         return cache[key]
     }
 
     fun getAll(): Map<String, V> {
+        if (!isLoaded) load()
         return HashMap(cache)
     }
 
@@ -60,6 +64,8 @@ internal class LoadStoreCache<V>(
             }.toMap()
         clear()
         putAll(values)
+        isLoaded = true
+        onLoad?.invoke()
     }
 
     fun store(values: MutableMap<String, V> = cache) {
@@ -94,10 +100,11 @@ internal fun getFlagStorage(
     deploymentKey: String,
     instanceName: String,
     storage: Storage,
+    merger: () -> Unit,
 ): LoadStoreCache<EvaluationFlag> {
     val truncatedDeployment = deploymentKey.takeLast(6)
     val namespace = "amp-exp-$instanceName-$truncatedDeployment-flags"
-    return LoadStoreCache(namespace, storage, ::decodeFlagFromStorage, ::encodeFlagToStorage)
+    return LoadStoreCache(namespace, storage, ::decodeFlagFromStorage, ::encodeFlagToStorage, merger)
 }
 
 internal fun decodeVariantFromStorage(storageValue: String): Variant? {