diff --git a/synodic_client/application/qt.py b/synodic_client/application/qt.py
index 1df55c8..0a6b8d7 100644
--- a/synodic_client/application/qt.py
+++ b/synodic_client/application/qt.py
@@ -6,6 +6,7 @@
 
 from porringer.api import API, APIParameters
 from porringer.schema import ListPluginsParameters, LocalConfiguration
+from PySide6.QtCore import Qt
 from PySide6.QtWidgets import QApplication
 
 from synodic_client.application.screen.screen import Screen
@@ -42,14 +43,15 @@ def application() -> None:
     app = QApplication([])
     app.setQuitOnLastWindowClosed(False)
 
-    screen = Screen()
+    # Reduce CPU usage when idle - process events less aggressively
+    app.setAttribute(Qt.ApplicationAttribute.AA_CompressHighFrequencyEvents)
 
-    # Store tray screen as instance attribute using object.__setattr__
-    # to avoid type checking issues with dynamic attributes
-    tray_screen = TrayScreen(app, client, icon, screen.window)
-    object.__setattr__(app, 'tray', tray_screen)
+    _screen = Screen()
+    _tray = TrayScreen(app, client, icon, _screen.window)
 
-    app.exec_()
+    # sys.exit ensures proper cleanup and exit code propagation
+    # Leading underscore indicates references kept alive intentionally until exec() returns
+    sys.exit(app.exec())
 
 
 if __name__ == '__main__':
diff --git a/synodic_client/application/screen/screen.py b/synodic_client/application/screen/screen.py
index 92cd4a2..f2a7e9a 100644
--- a/synodic_client/application/screen/screen.py
+++ b/synodic_client/application/screen/screen.py
@@ -9,13 +9,26 @@ class MainWindow(QMainWindow):
     def __init__(self) -> None:
         """Initialize the main window."""
         super().__init__()
+        self.setWindowTitle('Synodic Client')
+
+    def show(self) -> None:
+        """Show the window, initializing UI lazily on first show."""
+        # Future: Initialize heavy UI components here on first show
+        super().show()
 
 
 class Screen:
     """Screen class for the Synodic Client application."""
 
-    def __init__(self):
-        """Initialize the screen."""
-        self.window = MainWindow()
+    _window: MainWindow | None = None
+
+    @property
+    def window(self) -> MainWindow:
+        """Lazily create the main window on first access.
 
-        self.window.setWindowTitle('Synodic Client')
+        Returns:
+            The MainWindow instance.
+        """
+        if self._window is None:
+            self._window = MainWindow()
+        return self._window
diff --git a/synodic_client/updater.py b/synodic_client/updater.py
index 3e3f470..caca249 100644
--- a/synodic_client/updater.py
+++ b/synodic_client/updater.py
@@ -462,7 +462,7 @@ def _apply_windows_update(self, current_exe: Path, new_exe: Path, backup_path: P
         if sys.platform == 'win32':
             # CREATE_NEW_CONSOLE = 0x00000200, DETACHED_PROCESS = 0x00000008
             flags = 0x00000200 | 0x00000008
-        
+
         subprocess.Popen(
             ['cmd', '/c', str(script_path)],
             creationflags=flags,