diff --git a/client/src/api/alerts.ts b/client/src/api/alerts.ts
index 97c411a..d7d98cb 100644
--- a/client/src/api/alerts.ts
+++ b/client/src/api/alerts.ts
@@ -1,5 +1,12 @@
 import { request } from './request'
 
+export enum AlertStatuses {
+	OK = 'ok',
+	ALERT_PENDING = 'alert_pending',
+	ALERTING = 'alerting',
+	OK_PENDING = 'ok_pending',
+}
+
 export type AlertInfo = {
 	id: number
 	name: string
@@ -8,8 +15,8 @@ export type AlertInfo = {
 	customMessage: string
 	customResolvedMessage: string
 	triggerInterval: number
-	lastStatus: string
-	lastStatusAt: string
+	lastStatus: AlertStatuses
+	lastStatusAt: number
 }
 
 export const getAlerts = () => request<AlertInfo[]>('/api/alerts')
diff --git a/client/src/api/contactPoints.ts b/client/src/api/contactPoints.ts
index 0c162c8..70ae984 100644
--- a/client/src/api/contactPoints.ts
+++ b/client/src/api/contactPoints.ts
@@ -25,7 +25,7 @@ export const updateContactPoint = ({ id, ...body }: ContactPointInfo) =>
 	})
 
 export const deleteContactPoint = (id: number) =>
-	request<ContactPointInfo>(
+	request<void, 'void'>(
 		`/api/contact-points/${id}`,
 		{ method: 'DELETE' },
 		'void'
diff --git a/client/src/api/dashboards.ts b/client/src/api/dashboards.ts
index b3468ca..c1e0ab2 100644
--- a/client/src/api/dashboards.ts
+++ b/client/src/api/dashboards.ts
@@ -43,7 +43,7 @@ export const updateDashboard = ({
 	})
 
 export const deleteDashboard = (id: number) =>
-	request<DashboardInfo>(
+	request<void, 'void'>(
 		`/api/dashboards/${id}`,
 		{
 			method: 'DELETE',
diff --git a/client/src/api/sensors.ts b/client/src/api/sensors.ts
index 7a9de58..7252e26 100644
--- a/client/src/api/sensors.ts
+++ b/client/src/api/sensors.ts
@@ -4,6 +4,7 @@ export type SensorInfo = {
 	id: number
 	name: string
 	authKey: string
+	lastContactAt?: number
 }
 
 export const getSensors = () => request<SensorInfo[]>('/api/sensors')
@@ -23,4 +24,4 @@ export const updateSensor = ({ id, ...body }: { id: number; name: string }) =>
 	})
 
 export const deleteSensor = (id: number) =>
-	request<SensorInfo>(`/api/sensors/${id}`, { method: 'DELETE' }, 'void')
+	request<void, 'void'>(`/api/sensors/${id}`, { method: 'DELETE' }, 'void')
diff --git a/client/src/assets/pages/_alerts-page.scss b/client/src/assets/pages/_alerts-page.scss
index 0a44707..4cc692b 100644
--- a/client/src/assets/pages/_alerts-page.scss
+++ b/client/src/assets/pages/_alerts-page.scss
@@ -5,4 +5,27 @@
 	.contact-points {
 		margin-bottom: 2rem;
 	}
+
+	.alert-status {
+		text-transform: uppercase;
+		padding: 0.2rem 0.4rem;
+		border-radius: var(--border-radius);
+		display: inline-flex;
+
+		&.status-ok {
+			background-color: #016101;
+			color: #fff;
+		}
+
+		&.status-alert_pending,
+		&.status-ok_pending {
+			background-color: #ff8c00;
+			color: #fff;
+		}
+
+		&.status-alerting {
+			background-color: #d22424;
+			color: #fff;
+		}
+	}
 }
diff --git a/client/src/pages/alerts/components/AlertStatus.tsx b/client/src/pages/alerts/components/AlertStatus.tsx
new file mode 100644
index 0000000..2940f84
--- /dev/null
+++ b/client/src/pages/alerts/components/AlertStatus.tsx
@@ -0,0 +1,25 @@
+import { AlertInfo, AlertStatuses } from '@/api/alerts'
+import { cn } from '@/utils/cn'
+import { formatDateTime } from '@/utils/formatDateTime'
+
+type Props = {
+	alert: Pick<AlertInfo, 'lastStatus' | 'lastStatusAt'>
+}
+
+const statusToStr = {
+	[AlertStatuses.OK]: 'OK',
+	[AlertStatuses.ALERT_PENDING]: 'Alert pending',
+	[AlertStatuses.ALERTING]: 'Alerting',
+	[AlertStatuses.OK_PENDING]: 'OK pending',
+} as const
+
+export const AlertStatus = ({ alert }: Props) => {
+	return (
+		<div
+			className={cn('alert-status', `status-${alert.lastStatus}`)}
+			title={`Last update at ${formatDateTime(alert.lastStatusAt)}`}
+		>
+			{statusToStr[alert.lastStatus]}
+		</div>
+	)
+}
diff --git a/client/src/pages/alerts/components/AlertsTable/AlertsTable.tsx b/client/src/pages/alerts/components/AlertsTable/AlertsTable.tsx
index 512fad8..79839f4 100644
--- a/client/src/pages/alerts/components/AlertsTable/AlertsTable.tsx
+++ b/client/src/pages/alerts/components/AlertsTable/AlertsTable.tsx
@@ -6,6 +6,7 @@ import { useState } from 'preact/hooks'
 import { useMutation, useQuery } from 'react-query'
 import { AlertFormModal } from './components/AlertFormModal'
 import { NoAlerts } from '../NoAlerts'
+import { AlertStatus } from '../AlertStatus'
 
 export const AlertsTable = () => {
 	const alerts = useQuery('/alerts', getAlerts, {
@@ -43,8 +44,8 @@ export const AlertsTable = () => {
 						{
 							key: 'lastStatus',
 							title: 'Last status',
-							render: (c) => c.lastStatus,
-							width: '10rem',
+							render: (c) => <AlertStatus alert={c} />,
+							width: '6rem',
 						},
 						{
 							key: 'actions',
diff --git a/client/src/pages/alerts/components/ContactPointsTable/ContactPointsTable.tsx b/client/src/pages/alerts/components/ContactPointsTable/ContactPointsTable.tsx
index 2fa7c31..786434b 100644
--- a/client/src/pages/alerts/components/ContactPointsTable/ContactPointsTable.tsx
+++ b/client/src/pages/alerts/components/ContactPointsTable/ContactPointsTable.tsx
@@ -53,7 +53,10 @@ export const ContactPointsTable = () => {
 							className: 'actions',
 							render: (c) => (
 								<div>
-									<button onClick={() => setShowDelete(c)} className="remove">
+									<button
+										onClick={() => setShowDelete(c)}
+										className="danger-variant"
+									>
 										<TrashIcon /> Delete
 									</button>
 									<button onClick={() => setEdited(c)}>
diff --git a/client/src/pages/sensors/SensorsPage.tsx b/client/src/pages/sensors/SensorsPage.tsx
index d650ab3..694ce71 100644
--- a/client/src/pages/sensors/SensorsPage.tsx
+++ b/client/src/pages/sensors/SensorsPage.tsx
@@ -8,6 +8,7 @@ import { SensorFormModal } from './components/SensorFormModal'
 import { useConfirmModal } from '@/contexts/ConfirmModalsContext'
 import { SensorDetailModal } from './components/SensorDetailModal'
 import { NoSensors } from './components/NoSensors'
+import { formatDateTime } from '@/utils/formatDateTime'
 
 export const SensorsPage = () => {
 	const sensors = useQuery(['/sensors'], getSensors)
@@ -43,6 +44,13 @@ export const SensorsPage = () => {
 					columns={[
 						{ key: 'type', title: 'ID', render: (c) => c.id, width: '1rem' },
 						{ key: 'name', title: 'Name', render: (c) => c.name, scale: 1 },
+						{
+							key: 'lastContact',
+							title: 'Last Contact At',
+							render: (c) =>
+								c.lastContactAt ? formatDateTime(c.lastContactAt) : 'Never',
+							width: '10rem',
+						},
 						{
 							key: 'actions',
 							title: 'Actions',
diff --git a/client/src/utils/formatDateTime.ts b/client/src/utils/formatDateTime.ts
new file mode 100644
index 0000000..6d8313c
--- /dev/null
+++ b/client/src/utils/formatDateTime.ts
@@ -0,0 +1,11 @@
+export const formatDateTime = (unixInSeconds: number) => {
+	const date = new Date(unixInSeconds * 1000)
+
+	return date.toLocaleDateString(undefined, {
+		year: 'numeric',
+		month: 'short',
+		day: 'numeric',
+		hour: 'numeric',
+		minute: 'numeric',
+	})
+}
diff --git a/server/database/migrations/1711981974871_add_last_contact.sql b/server/database/migrations/1711981974871_add_last_contact.sql
new file mode 100644
index 0000000..71cd9f4
--- /dev/null
+++ b/server/database/migrations/1711981974871_add_last_contact.sql
@@ -0,0 +1 @@
+ALTER TABLE sensors ADD COLUMN last_contact_at INTEGER;
\ No newline at end of file
diff --git a/server/models/sensors.go b/server/models/sensors.go
index c874cb3..d15cc3a 100644
--- a/server/models/sensors.go
+++ b/server/models/sensors.go
@@ -1,7 +1,8 @@
 package models
 
 type SensorItem struct {
-	Id      int64  `json:"id"`
-	Name    string `json:"name"`
-	AuthKey string `json:"authKey"`
+	Id            int64  `json:"id" db:"id"`
+	Name          string `json:"name" db:"name"`
+	AuthKey       string `json:"authKey" db:"auth_key"`
+	LastContactAt *int64 `json:"lastContactAt" db:"last_contact_at"`
 }
diff --git a/server/routes/alerts.go b/server/routes/alerts.go
index d3797a1..16e32e7 100644
--- a/server/routes/alerts.go
+++ b/server/routes/alerts.go
@@ -12,8 +12,8 @@ type postAndPutAlertsBody struct {
 	Name                  string `json:"name" binding:"required"`
 	Condition             string `json:"condition" binding:"required"`
 	TriggerInterval       int64  `json:"triggerInterval" binding:"required"`
-	CustomMessage         string `json:"customMessage" binding:"required"`
-	CustomResolvedMessage string `json:"customResolvedMessage" binding:"required"`
+	CustomMessage         string `json:"customMessage"`
+	CustomResolvedMessage string `json:"customResolvedMessage"`
 }
 
 func GetAlerts(s *app.Server) gin.HandlerFunc {
@@ -32,7 +32,9 @@ func GetAlerts(s *app.Server) gin.HandlerFunc {
 func PostAlerts(s *app.Server) gin.HandlerFunc {
 	return func(c *gin.Context) {
 		body := postAndPutAlertsBody{}
-		bindJSONBodyOrAbort(c, &body)
+		if err := bindJSONBodyOrAbort(c, &body); err != nil {
+			return
+		}
 
 		alert, err := s.Services.Alerts.Create(body.ContactPointId, body.Name, body.Condition, body.TriggerInterval, body.CustomMessage, body.CustomResolvedMessage)
 
@@ -47,10 +49,15 @@ func PostAlerts(s *app.Server) gin.HandlerFunc {
 
 func PutAlert(s *app.Server) gin.HandlerFunc {
 	return func(c *gin.Context) {
-		alertId := getIntParamOrAbort(c, "alertId")
+		alertId, err := getIntParamOrAbort(c, "alertId")
+		if err != nil {
+			return
+		}
 
 		body := postAndPutAlertsBody{}
-		bindJSONBodyOrAbort(c, &body)
+		if err := bindJSONBodyOrAbort(c, &body); err != nil {
+			return
+		}
 
 		alert, err := s.Services.Alerts.Update(alertId, body.ContactPointId, body.Name, body.Condition, body.TriggerInterval, body.CustomMessage, body.CustomResolvedMessage)
 
@@ -65,7 +72,10 @@ func PutAlert(s *app.Server) gin.HandlerFunc {
 
 func GetAlert(s *app.Server) gin.HandlerFunc {
 	return func(c *gin.Context) {
-		alertId := getIntParamOrAbort(c, "alertId")
+		alertId, err := getIntParamOrAbort(c, "alertId")
+		if err != nil {
+			return
+		}
 
 		alert, err := s.Services.Alerts.GetById(alertId)
 
@@ -80,7 +90,10 @@ func GetAlert(s *app.Server) gin.HandlerFunc {
 
 func DeleteAlert(s *app.Server) gin.HandlerFunc {
 	return func(c *gin.Context) {
-		alertId := getIntParamOrAbort(c, "alertId")
+		alertId, err := getIntParamOrAbort(c, "alertId")
+		if err != nil {
+			return
+		}
 
 		if err := s.Services.Alerts.DeleteById(alertId); err != nil {
 			c.AbortWithError(http.StatusInternalServerError, err)
diff --git a/server/routes/auth.go b/server/routes/auth.go
index a1c7954..e7ba24f 100644
--- a/server/routes/auth.go
+++ b/server/routes/auth.go
@@ -15,7 +15,9 @@ type postLoginBody struct {
 func Login(s *app.Server) gin.HandlerFunc {
 	return func(c *gin.Context) {
 		body := postLoginBody{}
-		bindJSONBodyOrAbort(c, &body)
+		if err := bindJSONBodyOrAbort(c, &body); err != nil {
+			return
+		}
 
 		if body.Password != s.Config.AuthPassword || body.Username != s.Config.AuthUsername {
 			c.AbortWithStatus(401)
diff --git a/server/routes/contact_points.go b/server/routes/contact_points.go
index f2ecb1f..51ab714 100644
--- a/server/routes/contact_points.go
+++ b/server/routes/contact_points.go
@@ -34,8 +34,10 @@ func GetContactPoints(s *app.Server) gin.HandlerFunc {
 func PostContactPoints(s *app.Server) gin.HandlerFunc {
 	return func(c *gin.Context) {
 		body := postOrPutContactPointsBody{}
-		bindJSONBodyOrAbort(c, &body)
 
+		if err := bindJSONBodyOrAbort(c, &body); err != nil {
+			return
+		}
 		contactPoint, err := s.Services.ContactPoints.Create(body.Name, body.Type, body.TypeConfig)
 
 		if err != nil {
@@ -49,10 +51,15 @@ func PostContactPoints(s *app.Server) gin.HandlerFunc {
 
 func PutContactPoint(s *app.Server) gin.HandlerFunc {
 	return func(c *gin.Context) {
-		contactPointId := getIntParamOrAbort(c, "contactPointId")
+		contactPointId, err := getIntParamOrAbort(c, "contactPointId")
+		if err != nil {
+			return
+		}
 
 		body := postOrPutContactPointsBody{}
-		bindJSONBodyOrAbort(c, &body)
+		if err := bindJSONBodyOrAbort(c, &body); err != nil {
+			return
+		}
 
 		contactPoint, err := s.Services.ContactPoints.Update(contactPointId, body.Name, body.Type, body.TypeConfig)
 
@@ -67,7 +74,10 @@ func PutContactPoint(s *app.Server) gin.HandlerFunc {
 
 func GetContactPoint(s *app.Server) gin.HandlerFunc {
 	return func(c *gin.Context) {
-		contactPointId := getIntParamOrAbort(c, "contactPointId")
+		contactPointId, err := getIntParamOrAbort(c, "contactPointId")
+		if err != nil {
+			return
+		}
 
 		contactPoint, err := s.Services.ContactPoints.GetById(contactPointId)
 
@@ -82,9 +92,12 @@ func GetContactPoint(s *app.Server) gin.HandlerFunc {
 
 func DeleteContactPoint(s *app.Server) gin.HandlerFunc {
 	return func(c *gin.Context) {
-		contactPointId := getIntParamOrAbort(c, "contactPointId")
+		contactPointId, err := getIntParamOrAbort(c, "contactPointId")
+		if err != nil {
+			return
+		}
 
-		err := s.Services.ContactPoints.Delete(contactPointId)
+		err = s.Services.ContactPoints.Delete(contactPointId)
 
 		if err != nil {
 			c.AbortWithError(http.StatusInternalServerError, err)
@@ -98,7 +111,9 @@ func DeleteContactPoint(s *app.Server) gin.HandlerFunc {
 func TestContactPoint(s *app.Server) gin.HandlerFunc {
 	return func(c *gin.Context) {
 		body := testContactPointBody{}
-		bindJSONBodyOrAbort(c, &body)
+		if err := bindJSONBodyOrAbort(c, &body); err != nil {
+			return
+		}
 
 		err := s.Services.ContactPoints.Test(body.Type, body.TypeConfig)
 
diff --git a/server/routes/dashboards.go b/server/routes/dashboards.go
index 6c74950..bf6472f 100644
--- a/server/routes/dashboards.go
+++ b/server/routes/dashboards.go
@@ -33,7 +33,10 @@ func GetDashboards(s *app.Server) gin.HandlerFunc {
 
 func GetDashboardById(s *app.Server) gin.HandlerFunc {
 	return func(c *gin.Context) {
-		id := getIntParamOrAbort(c, "id")
+		id, err := getIntParamOrAbort(c, "id")
+		if err != nil {
+			return
+		}
 
 		item, err := s.Services.Dashboards.GetById(id)
 
@@ -54,7 +57,10 @@ func GetDashboardById(s *app.Server) gin.HandlerFunc {
 func PostDashboard(s *app.Server) gin.HandlerFunc {
 	return func(c *gin.Context) {
 		body := postDashboardBody{}
-		bindJSONBodyOrAbort(c, &body)
+
+		if err := bindJSONBodyOrAbort(c, &body); err != nil {
+			return
+		}
 
 		item, err := s.Services.Dashboards.Create(body.Name, body.Contents)
 
@@ -69,11 +75,16 @@ func PostDashboard(s *app.Server) gin.HandlerFunc {
 
 func PutDashboard(s *app.Server) gin.HandlerFunc {
 	return func(c *gin.Context) {
-		id := getIntParamOrAbort(c, "id")
+		id, err := getIntParamOrAbort(c, "id")
+		if err != nil {
+			return
+		}
 
 		body := putDashboardBody{}
-		bindJSONBodyOrAbort(c, &body)
 
+		if err := bindJSONBodyOrAbort(c, &body); err != nil {
+			return
+		}
 		item, err := s.Services.Dashboards.Update(id, body.Name, body.Contents)
 
 		if err != nil {
@@ -87,9 +98,12 @@ func PutDashboard(s *app.Server) gin.HandlerFunc {
 
 func DeleteDashboard(s *app.Server) gin.HandlerFunc {
 	return func(c *gin.Context) {
-		id := getIntParamOrAbort(c, "id")
+		id, err := getIntParamOrAbort(c, "id")
+		if err != nil {
+			return
+		}
 
-		err := s.Services.Dashboards.Delete(id)
+		err = s.Services.Dashboards.Delete(id)
 
 		if err != nil {
 			c.AbortWithError(500, err)
diff --git a/server/routes/sensor_config.go b/server/routes/sensor_config.go
index 16d1e48..56db187 100644
--- a/server/routes/sensor_config.go
+++ b/server/routes/sensor_config.go
@@ -17,7 +17,9 @@ func PutSensorConfig(s *app.Server) gin.HandlerFunc {
 		sensor := c.Param("sensor")
 		key := c.Param("key")
 
-		bindJSONBodyOrAbort(c, &configValue)
+		if err := bindJSONBodyOrAbort(c, &configValue); err != nil {
+			return
+		}
 
 		if err := s.Services.SensorConfig.SetValue(sensor, key, configValue.Value); err != nil {
 			c.AbortWithError(500, err)
diff --git a/server/routes/sensor_values.go b/server/routes/sensor_values.go
index af3ec0f..811b499 100644
--- a/server/routes/sensor_values.go
+++ b/server/routes/sensor_values.go
@@ -25,9 +25,14 @@ func PostSensorValues(s *app.Server) gin.HandlerFunc {
 	return func(c *gin.Context) {
 		var newValue postSensorValueBody
 
-		bindJSONBodyOrAbort(c, &newValue)
+		if err := bindJSONBodyOrAbort(c, &newValue); err != nil {
+			return
+		}
 
-		sensorId := getIntParamOrAbort(c, "sensor")
+		sensorId, err := getIntParamOrAbort(c, "sensor")
+		if err != nil {
+			return
+		}
 
 		if _, err := s.Services.SensorValues.Push(sensorId, newValue.Value); err != nil {
 			c.AbortWithError(400, err)
@@ -42,7 +47,10 @@ func GetSensorValues(s *app.Server) gin.HandlerFunc {
 	return func(c *gin.Context) {
 		var query getSensorValuesQuery
 
-		sensorId := getIntParamOrAbort(c, "sensor")
+		sensorId, err := getIntParamOrAbort(c, "sensor")
+		if err != nil {
+			return
+		}
 
 		if err := c.ShouldBindQuery(&query); err != nil {
 			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
@@ -63,7 +71,10 @@ func GetSensorLatestValue(s *app.Server) gin.HandlerFunc {
 	return func(c *gin.Context) {
 		var query getLatestSensorValueQuery
 
-		sensorId := getIntParamOrAbort(c, "sensor")
+		sensorId, err := getIntParamOrAbort(c, "sensor")
+		if err != nil {
+			return
+		}
 
 		if err := c.ShouldBindQuery(&query); err != nil {
 			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
diff --git a/server/routes/sensors.go b/server/routes/sensors.go
index af46d10..d0aa1cc 100644
--- a/server/routes/sensors.go
+++ b/server/routes/sensors.go
@@ -29,7 +29,9 @@ func GetSensors(s *app.Server) gin.HandlerFunc {
 func PostSensors(s *app.Server) gin.HandlerFunc {
 	return func(c *gin.Context) {
 		body := postOrPutSensorsBody{}
-		bindJSONBodyOrAbort(c, &body)
+		if err := bindJSONBodyOrAbort(c, &body); err != nil {
+			return
+		}
 
 		sensor, err := s.Services.Sensors.Create(body.Name)
 
@@ -44,10 +46,15 @@ func PostSensors(s *app.Server) gin.HandlerFunc {
 
 func PutSensor(s *app.Server) gin.HandlerFunc {
 	return func(c *gin.Context) {
-		sensorId := getIntParamOrAbort(c, "sensor")
+		sensorId, err := getIntParamOrAbort(c, "sensor")
+		if err != nil {
+			return
+		}
 
 		body := postOrPutSensorsBody{}
-		bindJSONBodyOrAbort(c, &body)
+		if err := bindJSONBodyOrAbort(c, &body); err != nil {
+			return
+		}
 
 		sensor, err := s.Services.Sensors.Update(sensorId, body.Name)
 
@@ -62,10 +69,15 @@ func PutSensor(s *app.Server) gin.HandlerFunc {
 
 func GetSensor(s *app.Server) gin.HandlerFunc {
 	return func(c *gin.Context) {
-		sensorId := getIntParamOrAbort(c, "sensor")
+		sensorId, err := getIntParamOrAbort(c, "sensor")
+		if err != nil {
+			return
+		}
 
 		body := postOrPutSensorsBody{}
-		bindJSONBodyOrAbort(c, &body)
+		if err := bindJSONBodyOrAbort(c, &body); err != nil {
+			return
+		}
 
 		sensor, err := s.Services.Sensors.GetById(sensorId)
 
@@ -80,9 +92,12 @@ func GetSensor(s *app.Server) gin.HandlerFunc {
 
 func DeleteSensor(s *app.Server) gin.HandlerFunc {
 	return func(c *gin.Context) {
-		sensorId := getIntParamOrAbort(c, "sensor")
+		sensorId, err := getIntParamOrAbort(c, "sensor")
+		if err != nil {
+			return
+		}
 
-		err := s.Services.Sensors.DeleteById(sensorId)
+		err = s.Services.Sensors.DeleteById(sensorId)
 
 		if err != nil {
 			c.AbortWithError(http.StatusInternalServerError, err)
diff --git a/server/routes/utils.go b/server/routes/utils.go
index b11b7cd..124c35f 100644
--- a/server/routes/utils.go
+++ b/server/routes/utils.go
@@ -6,19 +6,24 @@ import (
 	"github.com/gin-gonic/gin"
 )
 
-func getIntParamOrAbort(c *gin.Context, key string) int64 {
+func getIntParamOrAbort(c *gin.Context, key string) (int64, error) {
 	value := c.Param(key)
 	val, err := strconv.ParseInt(value, 10, 64)
 
 	if err != nil {
 		c.AbortWithStatusJSON(400, gin.H{"error": "Invalid " + key})
+
+		return 0, err
 	}
 
-	return val
+	return val, nil
 }
 
-func bindJSONBodyOrAbort(c *gin.Context, body interface{}) {
+func bindJSONBodyOrAbort(c *gin.Context, body interface{}) error {
 	if err := c.ShouldBindJSON(body); err != nil {
 		c.AbortWithStatusJSON(400, gin.H{"error": err.Error()})
+		return err
 	}
+
+	return nil
 }
diff --git a/server/services/sensor_values_service.go b/server/services/sensor_values_service.go
index 72bd764..0868c18 100644
--- a/server/services/sensor_values_service.go
+++ b/server/services/sensor_values_service.go
@@ -19,7 +19,13 @@ func (s *SensorValuesService) Push(sensorId int64, value float64) (int64, error)
 	res, err := s.ctx.DB.Exec("INSERT INTO sensor_values (timestamp, sensor_id, value) VALUES (?, ?, ?)", time.Now().Unix(), sensorId, value)
 
 	if err != nil {
-		return 0, err
+		return 0, fmt.Errorf("failed to insert sensor value: %v", err)
+	}
+
+	_, err = s.ctx.DB.Exec("UPDATE sensors SET last_contact_at = ? WHERE id = ?", time.Now().Unix(), sensorId)
+
+	if err != nil {
+		return 0, fmt.Errorf("failed to update last_contact_at: %v", err)
 	}
 
 	return res.LastInsertId()
diff --git a/server/services/sensors_service.go b/server/services/sensors_service.go
index 3e62f0c..5fd14ce 100644
--- a/server/services/sensors_service.go
+++ b/server/services/sensors_service.go
@@ -3,7 +3,6 @@ package services
 import (
 	"basic-sensor-receiver/models"
 	"crypto/rand"
-	"database/sql"
 	"math/big"
 )
 
@@ -12,32 +11,10 @@ type SensorsService struct {
 }
 
 func (s *SensorsService) GetList() ([]models.SensorItem, error) {
-	sensors := make([]models.SensorItem, 0)
+	sensors := []models.SensorItem{}
 
-	rows, err := s.ctx.DB.Query("SELECT id, name, auth_key FROM sensors")
+	err := s.ctx.DB.Select(&sensors, "SELECT id, name, auth_key, last_contact_at FROM sensors")
 
-	if err != nil {
-		if err == sql.ErrNoRows {
-			return sensors, nil
-		}
-
-		return nil, err
-	}
-
-	defer rows.Close()
-
-	for rows.Next() {
-		item := models.SensorItem{}
-
-		err := rows.Scan(&item.Id, &item.Name, &item.AuthKey)
-		if err != nil {
-			return nil, err
-		}
-
-		sensors = append(sensors, item)
-	}
-
-	err = rows.Err()
 	if err != nil {
 		return nil, err
 	}
@@ -75,9 +52,8 @@ func (s *SensorsService) Create(name string) (*models.SensorItem, error) {
 func (s *SensorsService) GetById(id int64) (*models.SensorItem, error) {
 	item := models.SensorItem{}
 
-	row := s.ctx.DB.QueryRow("SELECT id, name, auth_key FROM sensors WHERE id = ?", id)
+	err := s.ctx.DB.Get(&item, "SELECT id, name, auth_key, last_contact_at FROM sensors WHERE id = $1", id)
 
-	err := row.Scan(&item.Id, &item.Name, &item.AuthKey)
 	if err != nil {
 		return nil, err
 	}