diff --git a/renderer/app.js b/renderer/app.js
index 83da3a7..4d681a2 100644
--- a/renderer/app.js
+++ b/renderer/app.js
@@ -229,18 +229,43 @@ function _isHistoryTabActive() {
   const tab = document.querySelector('.tab.active');
   return !!(tab && tab.dataset.view === 'history');
 }
-document.querySelectorAll('.tab').forEach(tab => {
-  tab.addEventListener('click', () => {
-    document.querySelectorAll('.tab').forEach(t => t.classList.remove('active'));
-    document.querySelectorAll('.view').forEach(v => v.classList.remove('active'));
+// Cache the tab/view collections once and use event delegation on the parent
+// so tab switches don't trigger three querySelectorAll walks per click.
+(() => {
+  const tabs = Array.from(document.querySelectorAll('.tab'));
+  const views = Array.from(document.querySelectorAll('.view'));
+  const tabsByView = {};
+  const viewsById = {};
+  for (const t of tabs) tabsByView[t.dataset.view] = t;
+  for (const v of views) viewsById[v.id] = v;
+  let activeTab = tabs.find(t => t.classList.contains('active')) || tabs[0];
+
+  const handle = (target) => {
+    const tab = target.closest('.tab');
+    if (!tab || tab === activeTab) return;
+    if (activeTab) {
+      activeTab.classList.remove('active');
+      const prevView = viewsById[`${activeTab.dataset.view}-view`];
+      if (prevView) prevView.classList.remove('active');
+    }
     tab.classList.add('active');
-    document.getElementById(`${tab.dataset.view}-view`).classList.add('active');
+    const nextView = viewsById[`${tab.dataset.view}-view`];
+    if (nextView) nextView.classList.add('active');
+    activeTab = tab;
     if (tab.dataset.view === 'history') {
       _historyDirty = false;
       loadHistory();
     }
-  });
-});
+  };
+
+  const tabBar = tabs[0] && tabs[0].parentElement;
+  if (tabBar) {
+    tabBar.addEventListener('click', (e) => handle(e.target));
+  } else {
+    // Fallback: bind per-tab if somehow no common parent
+    tabs.forEach(t => t.addEventListener('click', () => handle(t)));
+  }
+})();
 
 // --- Hoster selection ---
 function accountHasCreds(name, account) {
@@ -1175,6 +1200,22 @@ function handleRowClick(e, row) {
 // --- Context menu ---
 let alwaysOnTopState = false;
 
+// Cache hoster-counts for the context menu. Invalidated on structural changes
+// to queueJobs (the length-based signature is good enough — a job's hoster
+// never changes after it's created).
+let _hosterCountsCache = { sig: '', result: new Map() };
+function _getHosterCounts() {
+  const sig = `${queueJobs.length}`;
+  if (_hosterCountsCache.sig === sig) return _hosterCountsCache.result;
+  const m = new Map();
+  for (let i = 0; i < queueJobs.length; i++) {
+    const h = queueJobs[i].hoster;
+    m.set(h, (m.get(h) || 0) + 1);
+  }
+  _hosterCountsCache = { sig, result: m };
+  return m;
+}
+
 function handleRowContextMenu(e, row) {
   e.preventDefault();
   const jobId = row.dataset.jobId;
@@ -1204,11 +1245,11 @@ function showContextMenu(x, y) {
   const startItem = menu.querySelector('[data-action="start-selected"]');
   if (startItem) startItem.textContent = n > 1 ? `Ausgewählte starten (${n})` : 'Ausgewählte starten';
 
-  // Dynamic "delete by hoster" submenu
+  // Dynamic "delete by hoster" submenu — cached count keyed by queue length
+  // so a right-click on a 5000-job queue doesn't rescan everything.
   const deleteHosterSubmenu = menu.querySelector('.ctx-hoster-delete-submenu');
   const deleteHosterContainer = menu.querySelector('.ctx-hoster-delete-items');
-  const hosterCounts = new Map();
-  queueJobs.forEach(j => hosterCounts.set(j.hoster, (hosterCounts.get(j.hoster) || 0) + 1));
+  const hosterCounts = _getHosterCounts();
   deleteHosterContainer.innerHTML = '';
   if (hosterCounts.size > 0) {
     deleteHosterSubmenu.style.display = '';
@@ -2698,10 +2739,17 @@ async function saveSettings(options = {}) {
     newHosterSettings[name] = hs;
   }
 
-  await window.api.saveHosterSettings(newHosterSettings);
-  await window.api.saveGlobalSettings(globalSettings);
-  config = await window.api.getConfig();
-  hosterSettings = config.hosterSettings || {};
+  // Fire both saves in parallel instead of serializing the two IPC round-trips.
+  // Skip the getConfig refetch — we just wrote it, we know the new state, and
+  // the round-trip added 100–200ms of UI stall per keystroke (autosave fires
+  // on every input change).
+  await Promise.all([
+    window.api.saveHosterSettings(newHosterSettings),
+    window.api.saveGlobalSettings(globalSettings)
+  ]);
+  config.hosterSettings = newHosterSettings;
+  config.globalSettings = globalSettings;
+  hosterSettings = newHosterSettings;
   clearTimeout(settingsSaveTimer);
 
   // Start/stop folder monitor based on settings
@@ -3358,9 +3406,11 @@ function renderRecentUploadsPanel() {
         if (selectedRecentIds.has(id)) selectedRecentIds.delete(id);
         else selectedRecentIds.add(id);
       } else if (e.shiftKey && selectedRecentIds.size > 0) {
-        // Use already-sorted DOM order (cheap) instead of re-sorting the full array.
-        const sortedOrders = Array.from(tbody.querySelectorAll('.recent-file-row'))
-          .map(r => parseInt(r.dataset.order, 10));
+        // Reuse the already-sorted array from the sort cache instead of
+        // querying every .recent-file-row in the DOM (O(visible) vs O(N)
+        // on large panels).
+        const sortedOrders = (_recentSortCache.result || sortRecentFiles(sessionFilesData))
+          .map(r => r.order);
         const lastIdx = sortedOrders.findIndex(o => selectedRecentIds.has(o));
         const curIdx = sortedOrders.indexOf(id);
         if (lastIdx >= 0 && curIdx >= 0) {