diff --git a/datajunction-ui/src/app/pages/NodePage/__tests__/NodePage.test.jsx b/datajunction-ui/src/app/pages/NodePage/__tests__/NodePage.test.jsx
index 1e8f756c8..79565e8b6 100644
--- a/datajunction-ui/src/app/pages/NodePage/__tests__/NodePage.test.jsx
+++ b/datajunction-ui/src/app/pages/NodePage/__tests__/NodePage.test.jsx
@@ -25,6 +25,62 @@ vi.mock('recharts', () => ({
   Tooltip: () => null,
 }));
 
+// Mock reactflow (lineage/dimensions/graph tabs). Tabs are lazy-loaded, so
+// reactflow is dynamically imported mid-render; loading the real lib inside
+// jsdom during render blocks the event loop. The dedicated tab tests cover
+// reactflow rendering — here we only need NodePage to mount the right tab.
+vi.mock('reactflow/dist/style.css', () => ({}));
+vi.mock('reactflow', async () => {
+  const React = await vi.importActual('react');
+  const { useState } = React;
+  const Passthrough = ({ children }) => <div>{children}</div>;
+  return {
+    __esModule: true,
+    default: ({ children, nodes, nodeTypes }) => (
+      <div data-testid="reactflow">
+        {(nodes || []).map(n => {
+          const NodeComp = nodeTypes?.[n.type];
+          return NodeComp ? (
+            <NodeComp key={n.id} data={n.data} />
+          ) : (
+            <div key={n.id}>{n.id}</div>
+          );
+        })}
+        {children}
+      </div>
+    ),
+    ReactFlowProvider: Passthrough,
+    Panel: Passthrough,
+    Background: () => null,
+    Controls: () => null,
+    MiniMap: () => null,
+    Handle: () => null,
+    Position: { Left: 'left', Right: 'right', Top: 'top', Bottom: 'bottom' },
+    MarkerType: { ArrowClosed: 'arrowclosed', Arrow: 'arrow' },
+    useNodesState: initial => {
+      const [n, s] = useState(initial || []);
+      return [n, s, () => {}];
+    },
+    useEdgesState: initial => {
+      const [e, s] = useState(initial || []);
+      return [e, s, () => {}];
+    },
+    addEdge: (params, eds) => [...(eds || []), params],
+  };
+});
+
+// Mock CodeMirror (materialization config editor). Like reactflow, it's pulled
+// in via a lazy tab and dynamically importing it (plus every language grammar
+// from codemirror-extensions-langs) mid-render blocks jsdom. The materialization
+// tab's own tests cover the editor.
+vi.mock('@uiw/react-codemirror', () => ({
+  __esModule: true,
+  default: ({ value }) => <div data-testid="codemirror">{value}</div>,
+}));
+vi.mock('@uiw/codemirror-extensions-langs', () => ({
+  langs: new Proxy({}, { get: () => () => [] }),
+}));
+
 // ResizeObserver is not defined in jsdom
 global.ResizeObserver = function (callback) {
   return { observe: () => {}, disconnect: () => {}, unobserve: () => {} };
diff --git a/datajunction-ui/src/app/pages/NodePage/index.jsx b/datajunction-ui/src/app/pages/NodePage/index.jsx
index d6ce87160..c38a19b00 100644
--- a/datajunction-ui/src/app/pages/NodePage/index.jsx
+++ b/datajunction-ui/src/app/pages/NodePage/index.jsx
@@ -1,28 +1,32 @@
 import * as React from 'react';
 import { useParams } from 'react-router-dom';
-import { useContext, useEffect, useState } from 'react';
+import { useContext, useEffect, useState, lazy, Suspense } from 'react';
 import Tab from '../../components/Tab';
 import NamespaceHeader from '../../components/NamespaceHeader';
-import NodeInfoTab from './NodeInfoTab';
-import NodeColumnTab from './NodeColumnTab';
-import NodeDataFlowTab from './NodeDataFlowTab';
-import NodeDimensionsTab from './NodeDimensionsTab';
-import NodeHistory from './NodeHistory';
 import NotebookDownload from './NotebookDownload';
 import DJClientContext from '../../providers/djclient';
-import NodeMaterializationTab from './NodeMaterializationTab';
-import NodePreAggregationsTab from './NodePreAggregationsTab';
 import ClientCodePopover from './ClientCodePopover';
 import WatchButton from './WatchNodeButton';
-import NodesWithDimension from './NodesWithDimension';
-import NodeColumnLineage from './NodeLineageTab';
 import EditIcon from '../../icons/EditIcon';
 import ChartIcon from '../../icons/ChartIcon';
 import AlertIcon from '../../icons/AlertIcon';
 import LoadingIcon from '../../icons/LoadingIcon';
-import NodeDependenciesTab from './NodeDependenciesTab';
 import { useNavigate } from 'react-router-dom';
 
+// Tabs are lazy-loaded so a node page only pulls the deps of the tab actually
+// shown. Otherwise every visit loads reactflow (lineage/dimensions/graph),
+// recharts (data flow) and codemirror (materialization) even for the Info tab.
+const NodeInfoTab = lazy(() => import('./NodeInfoTab'));
+const NodeColumnTab = lazy(() => import('./NodeColumnTab'));
+const NodeDataFlowTab = lazy(() => import('./NodeDataFlowTab'));
+const NodeDimensionsTab = lazy(() => import('./NodeDimensionsTab'));
+const NodeHistory = lazy(() => import('./NodeHistory'));
+const NodeMaterializationTab = lazy(() => import('./NodeMaterializationTab'));
+const NodePreAggregationsTab = lazy(() => import('./NodePreAggregationsTab'));
+const NodesWithDimension = lazy(() => import('./NodesWithDimension'));
+const NodeColumnLineage = lazy(() => import('./NodeLineageTab'));
+const NodeDependenciesTab = lazy(() => import('./NodeDependenciesTab'));
+
 export function NodePage() {
   const djClient = useContext(DJClientContext).DataJunctionAPI;
   const navigate = useNavigate();
@@ -317,7 +321,7 @@ export function NodePage() {
               </span>
             </div>
             <div className="dj-tabs-bar">{tabsList(node).map(buildTabs)}</div>
-            {tabToDisplay}
+            <Suspense fallback={<LoadingIcon />}>{tabToDisplay}</Suspense>
           </div>
         ) : node?.message !== undefined ? (
           <div className="message alert" style={{ margin: '20px' }}>