diff --git a/app/code/Magento/Signifyd/Model/CaseServices/UpdatingService.php b/app/code/Magento/Signifyd/Model/CaseServices/UpdatingService.php
index 870705db941cc..168ab67f8cf50 100644
--- a/app/code/Magento/Signifyd/Model/CaseServices/UpdatingService.php
+++ b/app/code/Magento/Signifyd/Model/CaseServices/UpdatingService.php
@@ -5,8 +5,8 @@
  */
 namespace Magento\Signifyd\Model\CaseServices;
 
+use Magento\Framework\Api\SimpleDataObjectConverter;
 use Magento\Framework\Exception\LocalizedException;
-use Magento\Framework\Exception\NotFoundException;
 use Magento\Signifyd\Api\CaseRepositoryInterface;
 use Magento\Signifyd\Api\Data\CaseInterface;
 use Magento\Signifyd\Model\CommentsHistoryUpdater;
@@ -73,7 +73,6 @@ public function __construct(
      * @param CaseInterface $case
      * @param array $data
      * @return void
-     * @throws NotFoundException
      * @throws LocalizedException
      */
     public function update(CaseInterface $case, array $data)
@@ -111,7 +110,7 @@ private function setCaseData(CaseInterface $case, array $data)
             'orderId'
         ];
         foreach ($data as $key => $value) {
-            $methodName = 'set' . ucfirst($key);
+            $methodName = 'set' . SimpleDataObjectConverter::snakeCaseToUpperCamelCase($key);
             if (!in_array($key, $notResolvedKeys) && method_exists($case, $methodName)) {
                 call_user_func([$case, $methodName], $value);
             }
diff --git a/app/code/Magento/Webapi/Controller/Rest/ParamsOverrider.php b/app/code/Magento/Webapi/Controller/Rest/ParamsOverrider.php
index 1d8ccc127cea9..d1a3c0c0f0864 100644
--- a/app/code/Magento/Webapi/Controller/Rest/ParamsOverrider.php
+++ b/app/code/Magento/Webapi/Controller/Rest/ParamsOverrider.php
@@ -197,7 +197,7 @@ private function isPropertyDeclaredInDataObject(
             $index = array_search($serviceMethodParamName, array_column($methodParams, 'name'));
             if ($index !== false) {
                 $paramObjectType = $methodParams[$index][MethodsMap::METHOD_META_TYPE];
-                $setter = 'set' . ucfirst(SimpleDataObjectConverter::snakeCaseToCamelCase($objectProperty));
+                $setter = 'set' . SimpleDataObjectConverter::snakeCaseToUpperCamelCase($objectProperty);
                 if (array_key_exists(
                     $setter,
                     $this->getMethodsMap()->getMethodsMap($paramObjectType)
diff --git a/lib/internal/Magento/Framework/Api/SimpleDataObjectConverter.php b/lib/internal/Magento/Framework/Api/SimpleDataObjectConverter.php
index a1f5acb4e60e7..49d824a4f2e5a 100644
--- a/lib/internal/Magento/Framework/Api/SimpleDataObjectConverter.php
+++ b/lib/internal/Magento/Framework/Api/SimpleDataObjectConverter.php
@@ -8,6 +8,9 @@
 use Magento\Framework\Convert\ConvertArray;
 use Magento\Framework\Reflection\DataObjectProcessor;
 
+/**
+ * Data object converter.
+ */
 class SimpleDataObjectConverter
 {
     /**
@@ -156,14 +159,13 @@ public static function snakeCaseToUpperCamelCase($input)
      */
     public static function snakeCaseToCamelCase($input)
     {
-        return lcfirst(str_replace(' ', '', ucwords(str_replace('_', ' ', $input))));
+        return lcfirst(self::snakeCaseToUpperCamelCase($input));
     }
 
     /**
      * Convert a CamelCase string read from method into field key in snake_case
      *
-     * e.g. DefaultShipping => default_shipping
-     *      Postcode => postcode
+     * For example [DefaultShipping => default_shipping, Postcode => postcode]
      *
      * @param string $name
      * @return string
diff --git a/lib/internal/Magento/Framework/App/Request/DataPersistor.php b/lib/internal/Magento/Framework/App/Request/DataPersistor.php
index bb3740aceb010..f0b8819621a1e 100644
--- a/lib/internal/Magento/Framework/App/Request/DataPersistor.php
+++ b/lib/internal/Magento/Framework/App/Request/DataPersistor.php
@@ -5,8 +5,12 @@
  */
 namespace Magento\Framework\App\Request;
 
+use Magento\Framework\Api\SimpleDataObjectConverter;
 use Magento\Framework\Session\SessionManagerInterface;
 
+/**
+ * Persist data to session.
+ */
 class DataPersistor implements DataPersistorInterface
 {
     /**
@@ -32,7 +36,7 @@ public function __construct(
      */
     public function set($key, $data)
     {
-        $method = 'set' . ucfirst($key) . 'Data';
+        $method = 'set' . SimpleDataObjectConverter::snakeCaseToUpperCamelCase($key) . 'Data';
         call_user_func_array([$this->session, $method], [$data]);
     }
 
@@ -44,7 +48,7 @@ public function set($key, $data)
      */
     public function get($key)
     {
-        $method = 'get' . ucfirst($key) . 'Data';
+        $method = 'get' . SimpleDataObjectConverter::snakeCaseToUpperCamelCase($key) . 'Data';
         return call_user_func_array([$this->session, $method], []);
     }
 
@@ -56,7 +60,7 @@ public function get($key)
      */
     public function clear($key)
     {
-        $method = 'uns' . ucfirst($key) . 'Data';
+        $method = 'uns' . SimpleDataObjectConverter::snakeCaseToUpperCamelCase($key) . 'Data';
         call_user_func_array([$this->session, $method], []);
     }
 }