diff --git a/resources/sql/autopatches/20160601.user.01.cache.sql b/resources/sql/autopatches/20160601.user.01.cache.sql
new file mode 100644
--- /dev/null
+++ b/resources/sql/autopatches/20160601.user.01.cache.sql
@@ -0,0 +1,11 @@
+CREATE TABLE {$NAMESPACE}_user.user_cache (
+  id INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
+  userPHID VARBINARY(64) NOT NULL,
+  cacheIndex BINARY(12) NOT NULL,
+  cacheKey VARCHAR(255) NOT NULL COLLATE {$COLLATE_TEXT},
+  cacheData LONGTEXT NOT NULL COLLATE {$COLLATE_TEXT},
+  cacheType VARCHAR(32) NOT NULL COLLATE {$COLLATE_TEXT},
+  UNIQUE KEY `key_usercache` (userPHID, cacheIndex),
+  KEY `key_cachekey` (cacheIndex),
+  KEY `key_cachetype` (cacheType)
+) ENGINE=InnoDB, COLLATE {$COLLATE_TEXT};
diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -3596,6 +3596,8 @@
     'PhabricatorUnsubscribedFromObjectEdgeType' => 'applications/transactions/edges/PhabricatorUnsubscribedFromObjectEdgeType.php',
     'PhabricatorUser' => 'applications/people/storage/PhabricatorUser.php',
     'PhabricatorUserBlurbField' => 'applications/people/customfield/PhabricatorUserBlurbField.php',
+    'PhabricatorUserCache' => 'applications/people/storage/PhabricatorUserCache.php',
+    'PhabricatorUserCacheType' => 'applications/people/cache/PhabricatorUserCacheType.php',
     'PhabricatorUserCardView' => 'applications/people/view/PhabricatorUserCardView.php',
     'PhabricatorUserConfigOptions' => 'applications/people/config/PhabricatorUserConfigOptions.php',
     'PhabricatorUserConfiguredCustomField' => 'applications/people/customfield/PhabricatorUserConfiguredCustomField.php',
@@ -3614,6 +3616,7 @@
     'PhabricatorUserLogView' => 'applications/people/view/PhabricatorUserLogView.php',
     'PhabricatorUserPHIDResolver' => 'applications/phid/resolver/PhabricatorUserPHIDResolver.php',
     'PhabricatorUserPreferences' => 'applications/settings/storage/PhabricatorUserPreferences.php',
+    'PhabricatorUserPreferencesCacheType' => 'applications/people/cache/PhabricatorUserPreferencesCacheType.php',
     'PhabricatorUserPreferencesEditor' => 'applications/settings/editor/PhabricatorUserPreferencesEditor.php',
     'PhabricatorUserPreferencesPHIDType' => 'applications/settings/phid/PhabricatorUserPreferencesPHIDType.php',
     'PhabricatorUserPreferencesQuery' => 'applications/settings/query/PhabricatorUserPreferencesQuery.php',
@@ -8368,6 +8371,8 @@
       'PhabricatorConduitResultInterface',
     ),
     'PhabricatorUserBlurbField' => 'PhabricatorUserCustomField',
+    'PhabricatorUserCache' => 'PhabricatorUserDAO',
+    'PhabricatorUserCacheType' => 'Phobject',
     'PhabricatorUserCardView' => 'AphrontTagView',
     'PhabricatorUserConfigOptions' => 'PhabricatorApplicationConfigOptions',
     'PhabricatorUserConfiguredCustomField' => array(
@@ -8397,7 +8402,8 @@
       'PhabricatorDestructibleInterface',
       'PhabricatorApplicationTransactionInterface',
     ),
-    'PhabricatorUserPreferencesEditor' => 'AlmanacEditor',
+    'PhabricatorUserPreferencesCacheType' => 'PhabricatorUserCacheType',
+    'PhabricatorUserPreferencesEditor' => 'PhabricatorApplicationTransactionEditor',
     'PhabricatorUserPreferencesPHIDType' => 'PhabricatorPHIDType',
     'PhabricatorUserPreferencesQuery' => 'PhabricatorCursorPagedPolicyAwareQuery',
     'PhabricatorUserPreferencesTransaction' => 'PhabricatorApplicationTransaction',
diff --git a/src/applications/auth/engine/PhabricatorAuthSessionEngine.php b/src/applications/auth/engine/PhabricatorAuthSessionEngine.php
--- a/src/applications/auth/engine/PhabricatorAuthSessionEngine.php
+++ b/src/applications/auth/engine/PhabricatorAuthSessionEngine.php
@@ -7,6 +7,7 @@
  * @task hisec    High Security
  * @task partial  Partial Sessions
  * @task onetime  One Time Login URIs
+ * @task cache    User Cache
  */
 final class PhabricatorAuthSessionEngine extends Phobject {
 
@@ -111,9 +112,8 @@
     $conn_r = $session_table->establishConnection('r');
     $session_key = PhabricatorHash::digest($session_token);
 
-    // NOTE: We're being clever here because this happens on every page load,
-    // and by joining we can save a query. This might be getting too clever
-    // for its own good, though...
+    $cache_parts = $this->getUserCacheQueryParts($conn_r);
+    list($cache_selects, $cache_joins, $cache_map) = $cache_parts;
 
     $info = queryfx_one(
       $conn_r,
@@ -125,12 +125,15 @@
           s.isPartial AS s_isPartial,
           s.signedLegalpadDocuments as s_signedLegalpadDocuments,
           u.*
+          %Q
         FROM %T u JOIN %T s ON u.phid = s.userPHID
-        AND s.type = %s AND s.sessionKey = %s',
+        AND s.type = %s AND s.sessionKey = %s %Q',
+      $cache_selects,
       $user_table->getTableName(),
       $session_table->getTableName(),
       $session_type,
-      $session_key);
+      $session_key,
+      $cache_joins);
 
     if (!$info) {
       return null;
@@ -141,14 +144,26 @@
       'sessionKey' => $session_key,
       'type' => $session_type,
     );
+
+    $cache_raw = array_fill_keys($cache_map, null);
     foreach ($info as $key => $value) {
       if (strncmp($key, 's_', 2) === 0) {
         unset($info[$key]);
         $session_dict[substr($key, 2)] = $value;
+        continue;
+      }
+
+      if (isset($cache_map[$key])) {
+        unset($info[$key]);
+        $cache_raw[$cache_map[$key]] = $value;
+        continue;
       }
     }
 
     $user = $user_table->loadFromArray($info);
+
+    $user->attachRawCacheData($cache_raw);
+
     switch ($session_type) {
       case PhabricatorAuthSession::TYPE_WEB:
         // Explicitly prevent bots and mailing lists from establishing web
@@ -732,4 +747,68 @@
     return PhabricatorHash::digest(implode(':', $parts));
   }
 
+
+/* -(  User Cache  )--------------------------------------------------------- */
+
+
+  /**
+   * @task cache
+   */
+  private function getUserCacheQueryParts(AphrontDatabaseConnection $conn) {
+    $cache_selects = array();
+    $cache_joins = array();
+    $cache_map = array();
+
+    $keys = array();
+
+    $cache_types = PhabricatorUserCacheType::getAllCacheTypes();
+    foreach ($cache_types as $cache_type) {
+      foreach ($cache_type->getAutoloadKeys() as $autoload_key) {
+        $keys[] = $autoload_key;
+      }
+    }
+
+    $cache_table = id(new PhabricatorUserCache())->getTableName();
+
+    $cache_idx = 1;
+    foreach ($keys as $key) {
+      $join_as = 'ucache_'.$cache_idx;
+      $select_as = 'ucache_'.$cache_idx.'_v';
+
+      $cache_selects[] = qsprintf(
+        $conn,
+        '%T.cacheData %T',
+        $join_as,
+        $select_as);
+
+      $cache_joins[] = qsprintf(
+        $conn,
+        'LEFT JOIN %T AS %T ON u.phid = %T.userPHID
+          AND %T.cacheIndex = %s',
+        $cache_table,
+        $join_as,
+        $join_as,
+        $join_as,
+        PhabricatorHash::digestForIndex($key));
+
+      $cache_map[$select_as] = $key;
+
+      $cache_idx++;
+    }
+
+    if ($cache_selects) {
+      $cache_selects = ', '.implode(', ', $cache_selects);
+    } else {
+      $cache_selects = '';
+    }
+
+    if ($cache_joins) {
+      $cache_joins = implode(' ', $cache_joins);
+    } else {
+      $cache_joins = '';
+    }
+
+    return array($cache_selects, $cache_joins, $cache_map);
+  }
+
 }
diff --git a/src/applications/base/controller/PhabricatorController.php b/src/applications/base/controller/PhabricatorController.php
--- a/src/applications/base/controller/PhabricatorController.php
+++ b/src/applications/base/controller/PhabricatorController.php
@@ -106,10 +106,9 @@
 
     PhabricatorEnv::setLocaleCode($user->getTranslation());
 
-    $preferences = $user->loadPreferences();
     if (PhabricatorEnv::getEnvConfig('darkconsole.enabled')) {
-      $dark_console = PhabricatorUserPreferences::PREFERENCE_DARK_CONSOLE;
-      if ($preferences->getPreference($dark_console) ||
+      $dark_console = PhabricatorDarkConsoleSetting::SETTINGKEY;
+      if ($user->getUserSetting($dark_console) ||
          PhabricatorEnv::getEnvConfig('darkconsole.always-on')) {
         $console = new DarkConsoleCore();
         $request->getApplicationConfiguration()->setConsole($console);
diff --git a/src/applications/people/cache/PhabricatorUserCacheType.php b/src/applications/people/cache/PhabricatorUserCacheType.php
new file mode 100644
--- /dev/null
+++ b/src/applications/people/cache/PhabricatorUserCacheType.php
@@ -0,0 +1,70 @@
+<?php
+
+abstract class PhabricatorUserCacheType extends Phobject {
+
+  final public function getViewer() {
+    return PhabricatorUser::getOmnipotentUser();
+  }
+
+  public function getAutoloadKeys() {
+    return array();
+  }
+
+  public function canManageKey($key) {
+    return false;
+  }
+
+  public function getDefaultValue() {
+    return array();
+  }
+
+  public function getValueFromStorage($value) {
+    return phutil_json_decode($value);
+  }
+
+  public function getValueForStorage($value) {
+    return phutil_json_encode($value);
+  }
+
+  public function newValueForUsers($key, array $users) {
+    return array();
+  }
+
+  final public function getUserCacheType() {
+    return $this->getPhobjectClassConstant('CACHETYPE');
+  }
+
+  public static function getAllCacheTypes() {
+    return id(new PhutilClassMapQuery())
+      ->setAncestorClass(__CLASS__)
+      ->setUniqueMethod('getUserCacheType')
+      ->execute();
+  }
+
+  public static function getCacheTypeForKey($key) {
+    $all = self::getAllCacheTypes();
+
+    foreach ($all as $type) {
+      if ($type->canManageKey($key)) {
+        return $type;
+      }
+    }
+
+    return null;
+  }
+
+  public static function requireCacheTypeForKey($key) {
+    $type = self::getCacheTypeForKey($key);
+
+    if (!$type) {
+      throw new Exception(
+        pht(
+          'Failed to load UserCacheType to manage key "%s". This cache type '.
+          'is required.',
+          $key));
+    }
+
+    return $type;
+  }
+
+}
diff --git a/src/applications/people/cache/PhabricatorUserPreferencesCacheType.php b/src/applications/people/cache/PhabricatorUserPreferencesCacheType.php
new file mode 100644
--- /dev/null
+++ b/src/applications/people/cache/PhabricatorUserPreferencesCacheType.php
@@ -0,0 +1,31 @@
+<?php
+
+final class PhabricatorUserPreferencesCacheType
+  extends PhabricatorUserCacheType {
+
+  const CACHETYPE = 'preferences';
+
+  const KEY_PREFERENCES = 'user.preferences.v1';
+
+  public function getAutoloadKeys() {
+    return array(
+      self::KEY_PREFERENCES,
+    );
+  }
+
+  public function canManageKey($key) {
+    return ($key === self::KEY_PREFERENCES);
+  }
+
+  public function newValueForUsers($key, array $users) {
+    $viewer = $this->getViewer();
+
+    $preferences = id(new PhabricatorUserPreferencesQuery())
+      ->setViewer($viewer)
+      ->withUserPHIDs(mpull($users, 'getPHID'))
+      ->execute();
+
+    return mpull($preferences, 'getPreferences', 'getUserPHID');
+  }
+
+}
diff --git a/src/applications/people/storage/PhabricatorUser.php b/src/applications/people/storage/PhabricatorUser.php
--- a/src/applications/people/storage/PhabricatorUser.php
+++ b/src/applications/people/storage/PhabricatorUser.php
@@ -5,6 +5,7 @@
  * @task image-cache Profile Image Cache
  * @task factors Multi-Factor Authentication
  * @task handles Managing Handles
+ * @task cache User Cache
  */
 final class PhabricatorUser
   extends PhabricatorUserDAO
@@ -61,6 +62,8 @@
 
   private $alternateCSRFString = self::ATTACHABLE;
   private $session = self::ATTACHABLE;
+  private $rawCacheData = array();
+  private $usableCacheData = array();
 
   private $authorities = array();
   private $handlePool;
@@ -487,6 +490,22 @@
       '(isPrimary = 1)');
   }
 
+  public function getUserSetting($key) {
+    $settings_key = PhabricatorUserPreferencesCacheType::KEY_PREFERENCES;
+    $settings = $this->requireCacheData($settings_key);
+
+    if (array_key_exists($key, $settings)) {
+      return $settings[$key];
+    }
+
+    $defaults = PhabricatorSetting::getAllEnabledSettings($this);
+    if (isset($defaults[$key])) {
+      return $defaults[$key]->getSettingDefaultValue();
+    }
+
+    return null;
+  }
+
   public function loadPreferences() {
     if ($this->preferences) {
       return $this->preferences;
@@ -1461,4 +1480,58 @@
   }
 
 
+/* -(  User Cache  )--------------------------------------------------------- */
+
+
+  /**
+   * @task cache
+   */
+  public function attachRawCacheData(array $data) {
+    $this->rawCacheData = $data + $this->rawCacheData;
+    return $this;
+  }
+
+
+  /**
+   * @task cache
+   */
+  protected function requireCacheData($key) {
+    if (isset($this->usableCacheData[$key])) {
+      return $this->usableCacheData[$key];
+    }
+
+    $type = PhabricatorUserCacheType::requireCacheTypeForKey($key);
+
+    if (isset($this->rawCacheData[$key])) {
+      $raw_value = $this->rawCacheData[$key];
+
+      $usable_value = $type->getValueFromStorage($raw_value);
+      $this->usableCacheData[$key] = $usable_value;
+
+      return $usable_value;
+    }
+
+    $usable_value = $type->getDefaultValue();
+
+    $user_phid = $this->getPHID();
+    if ($user_phid) {
+      $map = $type->newValueForUsers($key, array($this));
+      if (array_key_exists($user_phid, $map)) {
+        $usable_value = $map[$user_phid];
+        $raw_value = $type->getValueForStorage($usable_value);
+
+        $this->rawCacheData[$key] = $raw_value;
+        PhabricatorUserCache::writeCache(
+          $type,
+          $key,
+          $user_phid,
+          $raw_value);
+      }
+    }
+
+    $this->usableCacheData[$key] = $usable_value;
+
+    return $usable_value;
+  }
+
 }
diff --git a/src/applications/people/storage/PhabricatorUserCache.php b/src/applications/people/storage/PhabricatorUserCache.php
new file mode 100644
--- /dev/null
+++ b/src/applications/people/storage/PhabricatorUserCache.php
@@ -0,0 +1,110 @@
+<?php
+
+final class PhabricatorUserCache extends PhabricatorUserDAO {
+
+  protected $userPHID;
+  protected $cacheIndex;
+  protected $cacheKey;
+  protected $cacheData;
+  protected $cacheType;
+
+  protected function getConfiguration() {
+    return array(
+      self::CONFIG_TIMESTAMPS => false,
+      self::CONFIG_COLUMN_SCHEMA => array(
+        'cacheIndex' => 'bytes12',
+        'cacheKey' => 'text255',
+        'cacheData' => 'text',
+        'cacheType' => 'text32',
+      ),
+      self::CONFIG_KEY_SCHEMA => array(
+        'key_usercache' => array(
+          'columns' => array('userPHID', 'cacheIndex'),
+          'unique' => true,
+        ),
+        'key_cachekey' => array(
+          'columns' => array('cacheIndex'),
+        ),
+        'key_cachetype' => array(
+          'columns' => array('cacheType'),
+        ),
+      ),
+    ) + parent::getConfiguration();
+  }
+
+  public function save() {
+    $this->cacheIndex = Filesystem::digestForIndex($this->getCacheKey());
+    return parent::save();
+  }
+
+  public static function writeCache(
+    PhabricatorUserCacheType $type,
+    $key,
+    $user_phid,
+    $raw_value) {
+
+    if (PhabricatorEnv::isReadOnly()) {
+      return;
+    }
+
+    $table = new self();
+    $conn_w = $table->establishConnection('w');
+
+    $unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
+
+    queryfx(
+      $conn_w,
+      'INSERT INTO %T (userPHID, cacheIndex, cacheKey, cacheData, cacheType)
+        VALUES (%s, %s, %s, %s, %s)
+        ON DUPLICATE KEY UPDATE cacheData = VALUES(cacheData)',
+      $table->getTableName(),
+      $user_phid,
+      PhabricatorHash::digestForIndex($key),
+      $key,
+      $raw_value,
+      $type->getUserCacheType());
+
+    unset($unguarded);
+  }
+
+  public static function clearCache($key, $user_phid) {
+    if (PhabricatorEnv::isReadOnly()) {
+      return;
+    }
+
+    $table = new self();
+    $conn_w = $table->establishConnection('w');
+
+    $unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
+
+    queryfx(
+      $conn_w,
+      'DELETE FROM %T WHERE cacheIndex = %s AND userPHID = %s',
+      $table->getTableName(),
+      PhabricatorHash::digestForIndex($key),
+      $user_phid);
+
+    unset($unguarded);
+  }
+
+
+  public static function clearCacheForAllUsers($key) {
+    if (PhabricatorEnv::isReadOnly()) {
+      return;
+    }
+
+    $table = new self();
+    $conn_w = $table->establishConnection('w');
+
+    $unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
+
+    queryfx(
+      $conn_w,
+      'DELETE FROM %T WHERE cacheIndex = %s',
+      $table->getTableName(),
+      PhabricatorHash::digestForIndex($key));
+
+    unset($unguarded);
+  }
+
+}
diff --git a/src/applications/settings/editor/PhabricatorUserPreferencesEditor.php b/src/applications/settings/editor/PhabricatorUserPreferencesEditor.php
--- a/src/applications/settings/editor/PhabricatorUserPreferencesEditor.php
+++ b/src/applications/settings/editor/PhabricatorUserPreferencesEditor.php
@@ -1,7 +1,11 @@
 <?php
 
 final class PhabricatorUserPreferencesEditor
-  extends AlmanacEditor {
+  extends PhabricatorApplicationTransactionEditor {
+
+  public function getEditorApplicationClass() {
+    return 'PhabricatorSettingsApplication';
+  }
 
   public function getEditorObjectsDescription() {
     return pht('Settings');
@@ -129,4 +133,22 @@
     return $errors;
   }
 
+  protected function applyFinalEffects(
+    PhabricatorLiskDAO $object,
+    array $xactions) {
+
+    $user_phid = $object->getUserPHID();
+    if ($user_phid) {
+      PhabricatorUserCache::clearCache(
+        PhabricatorUserPreferencesCacheType::KEY_PREFERENCES,
+        $user_phid);
+    } else {
+      PhabricatorUserCache::clearCacheForAllUsers(
+        PhabricatorUserPreferencesCacheType::KEY_PREFERENCES);
+    }
+
+
+    return $xactions;
+  }
+
 }
diff --git a/src/applications/settings/storage/PhabricatorUserPreferences.php b/src/applications/settings/storage/PhabricatorUserPreferences.php
--- a/src/applications/settings/storage/PhabricatorUserPreferences.php
+++ b/src/applications/settings/storage/PhabricatorUserPreferences.php
@@ -165,6 +165,17 @@
     return false;
   }
 
+  // TODO: Remove this once all edits go through the Editor. For now, some
+  // old edits just do direct saves so make sure we nuke the cache.
+  public function save() {
+    PhabricatorUserCache::clearCache(
+      PhabricatorUserPreferencesCacheType::KEY_PREFERENCES,
+      $this->getUserPHID());
+
+    return parent::save();
+  }
+
+
 
 /* -(  PhabricatorPolicyInterface  )----------------------------------------- */