diff --git a/homes/common.nix b/homes/common.nix
index b68983f..2b452dd 100644
--- a/homes/common.nix
+++ b/homes/common.nix
@@ -16,6 +16,7 @@ in {
     ./../programs/lsd.nix
     ./../programs/neovim.nix
     ./../programs/starship.nix
+    ./../programs/yt-dlp.nix
   ];
   home = {
     stateVersion = "23.11";
@@ -107,7 +108,6 @@ in {
     gh.enable = true;
     gpg.enable = true;
     pandoc.enable = true;
-    yt-dlp.enable = true;
   };
   xdg = {
     dataFile = { "julia/config/startup.jl".source = ./../dotfiles/startup.jl; };
diff --git a/homes/darwin.nix b/homes/darwin.nix
index 4fb4601..d3c2982 100644
--- a/homes/darwin.nix
+++ b/homes/darwin.nix
@@ -1,4 +1,10 @@
 { config, lib, pkgs, pkgs-unstable, ... }: {
+
+  imports = [
+    ./../modules/defaults.nix
+    ./../programs/alttab.nix
+    ./../programs/taskbar.nix
+  ];
   home = {
     packages = with pkgs; [
       asitop
diff --git a/modules/defaults.nix b/modules/defaults.nix
new file mode 100644
index 0000000..dd5b2d7
--- /dev/null
+++ b/modules/defaults.nix
@@ -0,0 +1,93 @@
+# WARNING: This module was "vibe coded" by Claude Sonnet 4.5 Thinking
+# Nix modules are mostly boilerplace, so the logic is (mostly) mine, and the
+# rest comes from Claude. For reference, here was my prompt:
+#
+# I would like to write a new module for managing MacOS apps via the `defaults`
+# cli. Ideally, the syntax that I want to include in my home-manager config
+# should look like:
+#
+# ```nix
+# darwin-defaults = {
+#   "com.fpfxtknjju.wbgcdolfev" = {
+#     centerTasksAndButtons = false;
+#     pinList = [
+#       { action = "finderNewWindow"; bundleIdentifier = "com.apple.finder"; }
+#       { action = "firefoxNewWindow"; bundleIdentifier = "org.mozilla.firefox"; }
+#       { action = "launchOrActivateApp"; bundleIdentifier = "com.electron.logseq"; }
+#     ];
+#   };
+#   "com.lwouis.alt-tab-macos" = {
+#     screenRecordingPermissionSkipped = true;
+#     nextWindowGesture = 1;
+#   };
+# };
+# ```
+#
+# This should be fairly easy to implement, as `defaults` accepts (escaped) plist
+# strings, and Nix provides lib.generators.toPlist. Can you help me write the
+# module, please?
+
+{ config, lib, pkgs, ... }:
+let
+  inherit (pkgs.stdenv.hostPlatform) isDarwin;
+  inherit (lib) mkOption types mkIf;
+  inherit (lib.generators) toPlist;
+
+  cfg = config.defaults;
+
+  # Convert domain settings to defaults import command
+  domainToScript = domain: settings:
+    let
+      plistContent = toPlist { escape = true; } settings;
+      escapedDomain = lib.escapeShellArg domain;
+    in ''
+      $DRY_RUN_CMD echo "Applying defaults for ${domain}..."
+      $DRY_RUN_CMD /usr/bin/defaults import -app ${escapedDomain} - <<'EOF'
+      ${plistContent}
+      EOF
+      $DRY_RUN_CMD killall ${escapedDomain} && open -a ${escapedDomain}
+    '';
+
+  # Generate all activation scripts
+  activationScript =
+    lib.concatStringsSep "\n" (lib.mapAttrsToList domainToScript cfg);
+
+in {
+  options.defaults = mkOption {
+    type = types.attrsOf (types.attrsOf types.anything);
+    default = { };
+    description = ''
+      Configuration for macOS defaults by domain.
+
+      Each attribute set key represents a domain (typically an app bundle identifier),
+      and its value is an attribute set of preference keys and values that will be
+      converted to a plist and imported using the `defaults` command.
+
+      This module only works on macOS (Darwin) systems.
+    '';
+    example = lib.literalExpression ''
+      {
+        "com.apple.dock" = {
+          autohide = true;
+          tilesize = 48;
+          orientation = "left";
+        };
+        "com.apple.finder" = {
+          AppleShowAllFiles = true;
+          ShowPathbar = true;
+          FXEnableExtensionChangeWarning = false;
+        };
+      }
+    '';
+  };
+
+  config = mkIf (isDarwin && cfg != { }) {
+    home.activation.defaults = lib.hm.dag.entryAfter [ "writeBoundary" ] ''
+      if [[ -x /usr/bin/defaults ]]; then
+        ${activationScript}
+      else
+        echo "Warning: /usr/bin/defaults not found. Skipping darwin-defaults configuration."
+      fi
+    '';
+  };
+}
diff --git a/programs/alttab.nix b/programs/alttab.nix
new file mode 100644
index 0000000..1901f4d
--- /dev/null
+++ b/programs/alttab.nix
@@ -0,0 +1,10 @@
+{ ... }: {
+  defaults."AltTab" = {
+    appearanceStyle = 0;
+    nextWindowGesture = 1;
+    screenRecordingPermissionSkipped = true;
+    showFullscreenWindows = 0;
+    showHiddenWindows = 1;
+    updatePolicy = 2;
+  };
+}
diff --git a/programs/taskbar.nix b/programs/taskbar.nix
new file mode 100644
index 0000000..992c1f6
--- /dev/null
+++ b/programs/taskbar.nix
@@ -0,0 +1,49 @@
+{ ... }: {
+  defaults."Taskbar" = {
+    centerTasksAndButtons = false;
+    hideReviewOptions = true;
+    permissionsResetOnce = true;
+    pinList = [
+      {
+        action = "finderNewWindow";
+        bundleIdentifier = "com.apple.finder";
+      }
+      {
+        action = "launchOrActivateApp";
+        bundleIdentifier = "com.apple.AppStore";
+      }
+      {
+        action = "firefoxNewWindow";
+        bundleIdentifier = "org.mozilla.firefox";
+      }
+      {
+        action = "launchOrActivateApp";
+        bundleIdentifier = "com.apple.systempreferences";
+      }
+      {
+        action = "launchOrActivateApp";
+        bundleIdentifier = "com.electron.logseq";
+      }
+      {
+        action = "launchOrActivateApp";
+        bundleIdentifier = "org.mozilla.thunderbird";
+      }
+      {
+        action = "launchOrActivateApp";
+        bundleIdentifier =
+          "com.apple.Safari.WebApp.2F51A6D0-087A-438F-92D3-A73FE09CB4CC";
+      }
+      {
+        action = "launchOrActivateApp";
+        bundleIdentifier =
+          "com.apple.Safari.WebApp.5EC6478E-03A6-4147-8A4D-6EF3DE3F06D3";
+      }
+    ];
+    sendCrashReports = true;
+    showMenubarIcon = false;
+    showThumbnails = true;
+    showWindowTitleInThumbails = true;
+    taskViewMaxWidth = 200;
+    updatePolicy = 0;
+  };
+}
diff --git a/programs/yt-dlp.nix b/programs/yt-dlp.nix
new file mode 100644
index 0000000..fa2069a
--- /dev/null
+++ b/programs/yt-dlp.nix
@@ -0,0 +1,6 @@
+{ pkgs-unstable, ... }: {
+  programs.yt-dlp = {
+    enable = true;
+    package = pkgs-unstable.yt-dlp;
+  };
+}
diff --git a/systems/darwin/corianne.nix b/systems/darwin/corianne.nix
index 9628dcd..db34258 100644
--- a/systems/darwin/corianne.nix
+++ b/systems/darwin/corianne.nix
@@ -39,9 +39,10 @@ in {
   system.primaryUser = "millironx";
 
   system.defaults.dock = {
-    autohide = false;
+    autohide = true;
     minimize-to-application = true;
     mru-spaces = false;
+    orientation = "left";
     persistent-apps = let
       dedupDotApp = appName:
         if pkgs.lib.strings.hasSuffix ".app" appName then
@@ -69,20 +70,10 @@ in {
       };
     in [
       (sysApp "Firefox")
-      (chromeApp "Messages")
-      (sysApp "Signal")
       (sysApp "Thunderbird")
-      (localApp "Immich")
       (sysApp "Logseq")
       (sysApp "Zed")
       (sysApp "Steam")
-      (sysApp "Amperfy")
-      (sysApp "Microsoft Word")
-      (sysApp "Microsoft Excel")
-      (sysApp "Microsoft PowerPoint")
-      (localApp "Canvas")
-      (sysApp "Zotero")
-      (localApp "VetPrep")
       (chromeApp "Instinct Dashboard")
       (chromeApp "Carestream")
     ];
@@ -213,6 +204,7 @@ in {
       "slack"
       "stats"
       "steam"
+      "taskbar"
       "textmate"
       "thunderbird@esr"
       "ungoogled-chromium"