diff --git a/.env.example b/.env.example
index 945aeaf..4f0c304 100644
--- a/.env.example
+++ b/.env.example
@@ -1,2 +1,3 @@
 THQ_WS_AUTH_TOKEN=change-me
-THQ_WS_AUTH_REQUIRED=true
\ No newline at end of file
+THQ_WS_AUTH_REQUIRED=true
+GF_ADMIN_PASSWORD=change-me  # Grafana admin password – use a strong value in production
\ No newline at end of file
diff --git a/docker-compose.yml b/docker-compose.yml
index ed740e9..509cb77 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -32,5 +32,25 @@ services:
       timeout: 5s
       retries: 5
 
+  grafana:
+    image: grafana/grafana:11.6.0
+    depends_on:
+      db:
+        condition: service_healthy
+    environment:
+      GF_SECURITY_ADMIN_USER: admin
+      GF_SECURITY_ADMIN_PASSWORD: ${GF_ADMIN_PASSWORD:?set in .env or shell}
+      GF_AUTH_ANONYMOUS_ENABLED: "false"
+      GRAFANA_PG_USER: thq
+      GRAFANA_PG_PASSWORD: thq
+    volumes:
+      - grafana-data:/var/lib/grafana
+      - ./grafana/provisioning:/etc/grafana/provisioning
+      - ./grafana/dashboards:/var/lib/grafana/dashboards
+    ports:
+      - "3000:3000"
+    restart: unless-stopped
+
 volumes:
   db-data:
+  grafana-data:
diff --git a/grafana/dashboards/thq-overview.json b/grafana/dashboards/thq-overview.json
new file mode 100644
index 0000000..390c80c
--- /dev/null
+++ b/grafana/dashboards/thq-overview.json
@@ -0,0 +1,321 @@
+{
+  "annotations": { "list": [] },
+  "editable": true,
+  "fiscalYearStartMonth": 0,
+  "graphTooltip": 1,
+  "links": [],
+  "panels": [
+    {
+      "id": 1,
+      "title": "Location Logs Over Time",
+      "type": "timeseries",
+      "gridPos": { "h": 8, "w": 12, "x": 0, "y": 0 },
+      "datasource": { "type": "postgres", "uid": "thq-postgres" },
+      "fieldConfig": {
+        "defaults": {
+          "color": { "mode": "palette-classic" },
+          "custom": {
+            "lineWidth": 2,
+            "fillOpacity": 20,
+            "pointSize": 5,
+            "showPoints": "auto"
+          }
+        },
+        "overrides": []
+      },
+      "targets": [
+        {
+          "datasource": { "type": "postgres", "uid": "thq-postgres" },
+          "rawSql": "SELECT\n  date_trunc('hour', recorded_at) AS time,\n  device,\n  COUNT(*) AS count\nFROM location_logs\nWHERE recorded_at >= $__timeFrom() AND recorded_at <= $__timeTo()\nGROUP BY time, device\nORDER BY time",
+          "format": "time_series",
+          "refId": "A"
+        }
+      ]
+    },
+    {
+      "id": 2,
+      "title": "Log Events Over Time",
+      "type": "timeseries",
+      "gridPos": { "h": 8, "w": 12, "x": 12, "y": 0 },
+      "datasource": { "type": "postgres", "uid": "thq-postgres" },
+      "fieldConfig": {
+        "defaults": {
+          "color": { "mode": "palette-classic" },
+          "custom": {
+            "lineWidth": 2,
+            "fillOpacity": 20,
+            "pointSize": 5,
+            "showPoints": "auto"
+          }
+        },
+        "overrides": []
+      },
+      "targets": [
+        {
+          "datasource": { "type": "postgres", "uid": "thq-postgres" },
+          "rawSql": "SELECT\n  date_trunc('hour', recorded_at) AS time,\n  log_level,\n  COUNT(*) AS count\nFROM log_events\nWHERE recorded_at >= $__timeFrom() AND recorded_at <= $__timeTo()\nGROUP BY time, log_level\nORDER BY time",
+          "format": "time_series",
+          "refId": "A"
+        }
+      ]
+    },
+    {
+      "id": 3,
+      "title": "Total Location Logs",
+      "type": "stat",
+      "gridPos": { "h": 4, "w": 4, "x": 0, "y": 8 },
+      "datasource": { "type": "postgres", "uid": "thq-postgres" },
+      "fieldConfig": {
+        "defaults": {
+          "thresholds": {
+            "steps": [
+              { "color": "blue", "value": null }
+            ]
+          }
+        },
+        "overrides": []
+      },
+      "targets": [
+        {
+          "datasource": { "type": "postgres", "uid": "thq-postgres" },
+          "rawSql": "SELECT COUNT(*) AS \"Total\" FROM location_logs",
+          "format": "table",
+          "refId": "A"
+        }
+      ]
+    },
+    {
+      "id": 4,
+      "title": "Total Log Events",
+      "type": "stat",
+      "gridPos": { "h": 4, "w": 4, "x": 4, "y": 8 },
+      "datasource": { "type": "postgres", "uid": "thq-postgres" },
+      "fieldConfig": {
+        "defaults": {
+          "thresholds": {
+            "steps": [
+              { "color": "green", "value": null }
+            ]
+          }
+        },
+        "overrides": []
+      },
+      "targets": [
+        {
+          "datasource": { "type": "postgres", "uid": "thq-postgres" },
+          "rawSql": "SELECT COUNT(*) AS \"Total\" FROM log_events",
+          "format": "table",
+          "refId": "A"
+        }
+      ]
+    },
+    {
+      "id": 5,
+      "title": "Active Devices (24h)",
+      "type": "stat",
+      "gridPos": { "h": 4, "w": 4, "x": 8, "y": 8 },
+      "datasource": { "type": "postgres", "uid": "thq-postgres" },
+      "fieldConfig": {
+        "defaults": {
+          "thresholds": {
+            "steps": [
+              { "color": "orange", "value": null }
+            ]
+          }
+        },
+        "overrides": []
+      },
+      "targets": [
+        {
+          "datasource": { "type": "postgres", "uid": "thq-postgres" },
+          "rawSql": "SELECT COUNT(DISTINCT device) AS \"Devices\" FROM location_logs WHERE recorded_at >= NOW() - INTERVAL '24 hours'",
+          "format": "table",
+          "refId": "A"
+        }
+      ]
+    },
+    {
+      "id": 6,
+      "title": "Average Accuracy by Device",
+      "type": "bargauge",
+      "gridPos": { "h": 8, "w": 6, "x": 12, "y": 8 },
+      "datasource": { "type": "postgres", "uid": "thq-postgres" },
+      "fieldConfig": {
+        "defaults": {
+          "unit": "suffix: m",
+          "thresholds": {
+            "steps": [
+              { "color": "green", "value": null },
+              { "color": "yellow", "value": 30 },
+              { "color": "red", "value": 100 }
+            ]
+          }
+        },
+        "overrides": []
+      },
+      "options": {
+        "orientation": "horizontal",
+        "displayMode": "gradient"
+      },
+      "targets": [
+        {
+          "datasource": { "type": "postgres", "uid": "thq-postgres" },
+          "rawSql": "SELECT\n  device,\n  ROUND(AVG(accuracy)::numeric, 1) AS \"Avg Accuracy (m)\"\nFROM location_logs\nWHERE accuracy IS NOT NULL\n  AND recorded_at >= $__timeFrom() AND recorded_at <= $__timeTo()\nGROUP BY device\nORDER BY \"Avg Accuracy (m)\" DESC\nLIMIT 20",
+          "format": "table",
+          "refId": "A"
+        }
+      ]
+    },
+    {
+      "id": 7,
+      "title": "Accuracy Over Time",
+      "type": "timeseries",
+      "gridPos": { "h": 8, "w": 12, "x": 0, "y": 12 },
+      "datasource": { "type": "postgres", "uid": "thq-postgres" },
+      "fieldConfig": {
+        "defaults": {
+          "unit": "suffix: m",
+          "color": { "mode": "palette-classic" },
+          "custom": {
+            "lineWidth": 1,
+            "fillOpacity": 10,
+            "pointSize": 3,
+            "showPoints": "auto"
+          }
+        },
+        "overrides": []
+      },
+      "targets": [
+        {
+          "datasource": { "type": "postgres", "uid": "thq-postgres" },
+          "rawSql": "SELECT\n  date_trunc('hour', recorded_at) AS time,\n  device,\n  ROUND(AVG(accuracy)::numeric, 1) AS accuracy\nFROM location_logs\nWHERE accuracy IS NOT NULL\n  AND recorded_at >= $__timeFrom() AND recorded_at <= $__timeTo()\nGROUP BY time, device\nORDER BY time",
+          "format": "time_series",
+          "refId": "A"
+        }
+      ]
+    },
+    {
+      "id": 8,
+      "title": "Battery Level Over Time",
+      "type": "timeseries",
+      "gridPos": { "h": 8, "w": 12, "x": 12, "y": 16 },
+      "datasource": { "type": "postgres", "uid": "thq-postgres" },
+      "fieldConfig": {
+        "defaults": {
+          "unit": "percent",
+          "min": 0,
+          "max": 100,
+          "color": { "mode": "palette-classic" },
+          "custom": {
+            "lineWidth": 2,
+            "fillOpacity": 15,
+            "pointSize": 3,
+            "showPoints": "auto"
+          }
+        },
+        "overrides": []
+      },
+      "targets": [
+        {
+          "datasource": { "type": "postgres", "uid": "thq-postgres" },
+          "rawSql": "SELECT\n  date_trunc('hour', recorded_at) AS time,\n  device,\n  ROUND((AVG(battery_level) * 100)::numeric, 1) AS battery\nFROM location_logs\nWHERE battery_level IS NOT NULL\n  AND recorded_at >= $__timeFrom() AND recorded_at <= $__timeTo()\nGROUP BY time, device\nORDER BY time",
+          "format": "time_series",
+          "refId": "A"
+        }
+      ]
+    },
+    {
+      "id": 9,
+      "title": "Speed Over Time",
+      "type": "timeseries",
+      "gridPos": { "h": 8, "w": 12, "x": 0, "y": 20 },
+      "datasource": { "type": "postgres", "uid": "thq-postgres" },
+      "fieldConfig": {
+        "defaults": {
+          "unit": "velocityms",
+          "color": { "mode": "palette-classic" },
+          "custom": {
+            "lineWidth": 1,
+            "fillOpacity": 10,
+            "pointSize": 3,
+            "showPoints": "auto"
+          }
+        },
+        "overrides": []
+      },
+      "targets": [
+        {
+          "datasource": { "type": "postgres", "uid": "thq-postgres" },
+          "rawSql": "SELECT\n  date_trunc('hour', recorded_at) AS time,\n  device,\n  ROUND(AVG(speed)::numeric, 2) AS speed\nFROM location_logs\nWHERE speed IS NOT NULL\n  AND recorded_at >= $__timeFrom() AND recorded_at <= $__timeTo()\nGROUP BY time, device\nORDER BY time",
+          "format": "time_series",
+          "refId": "A"
+        }
+      ]
+    },
+    {
+      "id": 10,
+      "title": "Log Events by Level",
+      "type": "piechart",
+      "gridPos": { "h": 8, "w": 6, "x": 18, "y": 8 },
+      "datasource": { "type": "postgres", "uid": "thq-postgres" },
+      "transformations": [
+        {
+          "id": "rowsToFields",
+          "options": {
+            "mappings": [
+              { "fieldName": "log_level", "handlerKey": "field.name" },
+              { "fieldName": "count", "handlerKey": "field.value" }
+            ]
+          }
+        }
+      ],
+      "targets": [
+        {
+          "datasource": { "type": "postgres", "uid": "thq-postgres" },
+          "rawSql": "SELECT\n  log_level,\n  COUNT(*) AS count\nFROM log_events\nWHERE recorded_at >= $__timeFrom() AND recorded_at <= $__timeTo()\nGROUP BY log_level\nORDER BY count DESC",
+          "format": "table",
+          "refId": "A"
+        }
+      ]
+    },
+    {
+      "id": 11,
+      "title": "Recent Location Logs",
+      "type": "table",
+      "gridPos": { "h": 8, "w": 24, "x": 0, "y": 28 },
+      "datasource": { "type": "postgres", "uid": "thq-postgres" },
+      "targets": [
+        {
+          "datasource": { "type": "postgres", "uid": "thq-postgres" },
+          "rawSql": "SELECT\n  recorded_at AS time,\n  device,\n  state,\n  station_id,\n  line_id,\n  segment_id,\n  ROUND(latitude::numeric, 5) AS lat,\n  ROUND(longitude::numeric, 5) AS lon,\n  ROUND(accuracy::numeric, 1) AS accuracy,\n  ROUND(speed::numeric, 1) AS speed,\n  ROUND((battery_level * 100)::numeric, 0) AS \"battery%\"\nFROM location_logs\nWHERE recorded_at >= $__timeFrom() AND recorded_at <= $__timeTo()\nORDER BY recorded_at DESC\nLIMIT 100",
+          "format": "table",
+          "refId": "A"
+        }
+      ]
+    },
+    {
+      "id": 12,
+      "title": "Recent Log Events",
+      "type": "table",
+      "gridPos": { "h": 8, "w": 24, "x": 0, "y": 36 },
+      "datasource": { "type": "postgres", "uid": "thq-postgres" },
+      "targets": [
+        {
+          "datasource": { "type": "postgres", "uid": "thq-postgres" },
+          "rawSql": "SELECT\n  recorded_at AS time,\n  device,\n  log_type,\n  log_level,\n  message\nFROM log_events\nWHERE recorded_at >= $__timeFrom() AND recorded_at <= $__timeTo()\nORDER BY recorded_at DESC\nLIMIT 100",
+          "format": "table",
+          "refId": "A"
+        }
+      ]
+    }
+  ],
+  "refresh": "30s",
+  "schemaVersion": 39,
+  "tags": ["thq", "trainlcd"],
+  "templating": { "list": [] },
+  "time": { "from": "now-24h", "to": "now" },
+  "timepicker": {},
+  "timezone": "Asia/Tokyo",
+  "title": "THQ Overview",
+  "uid": "thq-overview"
+}
diff --git a/grafana/provisioning/dashboards/default.yml b/grafana/provisioning/dashboards/default.yml
new file mode 100644
index 0000000..aa5f7c1
--- /dev/null
+++ b/grafana/provisioning/dashboards/default.yml
@@ -0,0 +1,12 @@
+apiVersion: 1
+
+providers:
+  - name: default
+    orgId: 1
+    folder: ""
+    type: file
+    disableDeletion: false
+    editable: true
+    options:
+      path: /var/lib/grafana/dashboards
+      foldersFromFilesStructure: false
diff --git a/grafana/provisioning/datasources/postgres.yml b/grafana/provisioning/datasources/postgres.yml
new file mode 100644
index 0000000..06aed6b
--- /dev/null
+++ b/grafana/provisioning/datasources/postgres.yml
@@ -0,0 +1,16 @@
+apiVersion: 1
+
+datasources:
+  - name: THQ PostgreSQL
+    type: postgres
+    uid: thq-postgres
+    url: db:5432
+    database: thq
+    user: $__env{GRAFANA_PG_USER}
+    jsonData:
+      sslmode: disable
+      postgresVersion: 1800
+    secureJsonData:
+      password: $__env{GRAFANA_PG_PASSWORD}
+    isDefault: true
+    editable: true
diff --git a/src/storage.rs b/src/storage.rs
index d747d23..83c7d20 100644
--- a/src/storage.rs
+++ b/src/storage.rs
@@ -141,6 +141,14 @@ impl Storage {
             .execute(pool)
             .await?;
 
+        sqlx::query("CREATE INDEX IF NOT EXISTS idx_location_logs_recorded_at ON location_logs (recorded_at, device);")
+            .execute(pool)
+            .await?;
+
+        sqlx::query("CREATE INDEX IF NOT EXISTS idx_log_events_recorded_at ON log_events (recorded_at, log_level);")
+            .execute(pool)
+            .await?;
+
         Ok(())
     }