┌────────────────────────────┐
│ Revenue (This Month)       │ ← Label with time period
│                            │
│  $1,245,832               │ ← Big number (primary metric)
│  ↑ 15.3% vs last month    │ ← Trend indicator with comparison
│  ▂▃▅▆▇█ (sparkline)       │ ← Mini visualization
└────────────────────────────┘

npm install @tremor/react

npm install react-grid-layout

// Dashboard context for shared filters
const DashboardContext = createContext({
  filters: { dateRange: null, categories: [] },
  setFilters: () => {},
  refreshInterval: 30000
});

// Wrap dashboard with provider
<DashboardContext.Provider value={dashboardState}>
  <FilterPanel />
  <WidgetGrid />
</DashboardContext.Provider>

const eventSource = new EventSource('/api/dashboard/stream');
eventSource.onmessage = (event) => {
  const update = JSON.parse(event.data);
  updateWidget(update.widgetId, update.data);
};

import { Card, Grid, Metric, Text, BadgeDelta, AreaChart } from '@tremor/react';

function QuickDashboard({ data }) {
  return (
    <Grid numItems={1} numItemsSm={2} numItemsLg={4} className="gap-4">
      {/* KPI Cards */}
      <Card>
        <Text>Total Revenue</Text>
        <Metric>$45,231.89</Metric>
        <BadgeDelta deltaType="increase">+12.5%</BadgeDelta>
      </Card>

      <Card>
        <Text>Active Users</Text>
        <Metric>1,234</Metric>
        <BadgeDelta deltaType="decrease">-2.3%</BadgeDelta>
      </Card>

      {/* Chart Widget */}
      <Card className="lg:col-span-2">
        <Text>Revenue Trend</Text>
        <AreaChart
          data={data.revenue}
          index="date"
          categories={["revenue"]}
          valueFormatter={(value) => `$${value.toLocaleString()}`}
        />
      </Card>
    </Grid>
  );
}

import { Responsive, WidthProvider } from 'react-grid-layout';
import 'react-grid-layout/css/styles.css';

const ResponsiveGridLayout = WidthProvider(Responsive);

function CustomizableDashboard() {
  const [layouts, setLayouts] = useState(getStoredLayouts());

  return (
    <ResponsiveGridLayout
      layouts={layouts}
      breakpoints={{ lg: 1200, md: 996, sm: 768 }}
      cols={{ lg: 12, md: 10, sm: 6 }}
      rowHeight={60}
      onLayoutChange={(layout, layouts) => {
        setLayouts(layouts);
        localStorage.setItem('dashboardLayout', JSON.stringify(layouts));
      }}
      draggableHandle=".widget-header"
    >
      <div key="kpi1">
        <KPIWidget data={kpiData} />
      </div>
      <div key="chart1">
        <ChartWidget data={chartData} />
      </div>
      <div key="table1">
        <TableWidget data={tableData} />
      </div>
    </ResponsiveGridLayout>
  );
}

function useSSEUpdates(endpoint) {
  useEffect(() => {
    const eventSource = new EventSource(endpoint);

    eventSource.onmessage = (event) => {
      const update = JSON.parse(event.data);
      // Update specific widget or all widgets
      dispatch({ type: 'UPDATE_WIDGET', payload: update });
    };

    return () => eventSource.close();
  }, [endpoint]);
}

const ws = new WebSocket('ws://localhost:3000/dashboard');
ws.onmessage = (event) => {
  const data = JSON.parse(event.data);
  updateDashboard(data);
};
// Send filter changes to server
ws.send(JSON.stringify({ type: 'FILTER_CHANGE', filters }));

function useSmartPolling(fetchData, interval = 30000) {
  const [isPaused, setIsPaused] = useState(false);

  useEffect(() => {
    if (isPaused || document.hidden) return;

    const timer = setInterval(fetchData, interval);
    return () => clearInterval(timer);
  }, [isPaused, interval]);

  // Pause when tab inactive
  useEffect(() => {
    const handleVisibilityChange = () => {
      setIsPaused(document.hidden);
    };
    document.addEventListener('visibilitychange', handleVisibilityChange);
    return () => document.removeEventListener('visibilitychange', handleVisibilityChange);
  }, []);
}

function DashboardGrid({ widgets }) {
  const [visibleWidgets, setVisibleWidgets] = useState(new Set());

  return widgets.map(widget => (
    <LazyLoad
      key={widget.id}
      height={widget.height}
      offset={100}
      once
      placeholder={<WidgetSkeleton />}
    >
      <Widget {...widget} />
    </LazyLoad>
  ));
}

// Fetch all widget data simultaneously
const loadDashboard = async () => {
  const [kpis, charts, tables] = await Promise.all([
    fetchKPIs(),
    fetchChartData(),
    fetchTableData()
  ]);

  return { kpis, charts, tables };
};

function CachedWidget({ id, fetcher, ttl = 60000 }) {
  const cache = useRef({ data: null, timestamp: 0 });

  const getData = async () => {
    const now = Date.now();
    if (cache.current.data && now - cache.current.timestamp < ttl) {
      return cache.current.data;
    }

    const fresh = await fetcher();
    cache.current = { data: fresh, timestamp: now };
    return fresh;
  };

  // Use cached data while fetching fresh
  return <Widget data={cache.current.data} onRefresh={getData} />;
}

python scripts/optimize-dashboard-performance.py --analyze dashboard-config.json

// Use charts from data-viz skill
import { createChart } from '../data-viz/chart-factory';

const revenueChart = createChart('area', {
  data: revenueData,
  xAxis: 'date',
  yAxis: 'revenue',
  theme: dashboardTheme
});

// Use advanced tables from tables skill
import { DataGrid } from '../tables/data-grid';

<DataGrid
  data={transactions}
  columns={columnDefs}
  pagination={true}
  sorting={true}
  filtering={true}
/>

// Dashboard-specific tokens from design-tokens skill
const dashboardTokens = {
  '--dashboard-bg': 'var(--color-bg-secondary)',
  '--widget-bg': 'var(--color-white)',
  '--widget-shadow': 'var(--shadow-lg)',
  '--kpi-value-size': 'var(--font-size-4xl)',
  '--kpi-trend-positive': 'var(--color-success)',
  '--kpi-trend-negative': 'var(--color-error)'
};

// Advanced filter inputs from forms skill
import { DateRangePicker, MultiSelect } from '../forms/inputs';

<FilterPanel>
  <DateRangePicker onChange={handleDateChange} />
  <MultiSelect options={categories} onChange={handleCategoryFilter} />
</FilterPanel>

python scripts/calculate-kpi-metrics.py --data metrics.json --period monthly