diff --git a/frontend/src/component/application/ConnectedInstances/ConnectedInstances.tsx b/frontend/src/component/application/ConnectedInstances/ConnectedInstances.tsx
index ad9723be64..226a2cb4fd 100644
--- a/frontend/src/component/application/ConnectedInstances/ConnectedInstances.tsx
+++ b/frontend/src/component/application/ConnectedInstances/ConnectedInstances.tsx
@@ -1,99 +1,38 @@
-import { useMemo } from 'react';
+import { FC, useEffect, useMemo, useState } from 'react';
 import useApplication from 'hooks/api/getters/useApplication/useApplication';
-import { WarningAmber } from '@mui/icons-material';
 import { formatDateYMDHMS } from 'utils/formatDate';
 import { useRequiredPathParam } from 'hooks/useRequiredPathParam';
 import { useConnectedInstancesTable } from './useConnectedInstancesTable';
 import { ConnectedInstancesTable } from './ConnectedInstancesTable';
 import { IApplication } from 'interfaces/application';
-import { useQueryParam } from 'use-query-params';
-import { styled } from '@mui/material';
-import { ConditionallyRender } from 'component/common/ConditionallyRender/ConditionallyRender';
+import { Box, ToggleButton, ToggleButtonGroup } from '@mui/material';
+import { useApplicationOverview } from 'hooks/api/getters/useApplicationOverview/useApplicationOverview';
+import { useConnectedInstances } from 'hooks/api/getters/useConnectedInstances/useConnectedInstances';
 
-const Container = styled('div')(({ theme }) => ({
-    '* + *': {
-        marginBlockStart: theme.spacing(2),
-    },
-}));
-
-const EnvironmentSelectionContainer = styled('div')(({ theme }) => ({
-    label: {
-        '--padding-horizontal': theme.spacing(3),
-        '--padding-vertical': theme.spacing(1),
-        color: theme.palette.primary.main,
-        background: theme.palette.background,
-        paddingInline: 'var(--padding-horizontal)',
-        paddingBlock: 'var(--padding-vertical)',
-        border: `1px solid ${theme.palette.background.alternative}`,
-        borderInlineStart: 'none',
-        fontWeight: 'bold',
-        position: 'relative',
-
-        svg: {
-            color: theme.palette.warning.main,
-            position: 'absolute',
-            fontSize: theme.fontSizes.bodySize,
-            top: 'calc(var(--padding-horizontal) * .12)',
-            right: 'calc(var(--padding-horizontal) * .2)',
-        },
-    },
-    'label:first-of-type': {
-        borderInlineStart: `1px solid ${theme.palette.background.alternative}`,
-        borderRadius: `${theme.shape.borderRadiusMedium}px 0 0 ${theme.shape.borderRadiusMedium}px`,
-    },
-    'label:last-of-type': {
-        borderRadius: `0 ${theme.shape.borderRadiusMedium}px ${theme.shape.borderRadiusMedium}px 0`,
-    },
-    'label:has(input:checked)': {
-        background: theme.palette.background.alternative,
-        color: theme.palette.primary.contrastText,
-
-        svg: {
-            color: 'inherit',
-        },
-    },
-    'label:focus-within': {
-        outline: `2px solid ${theme.palette.background.alternative}`,
-        outlineOffset: theme.spacing(0.5),
-    },
-
-    fieldset: {
-        border: 'none',
-        padding: 0,
-        margin: 0,
-    },
-    legend: {
-        marginBlockEnd: theme.spacing(3),
-    },
-
-    '.visually-hidden': {
-        border: 0,
-        clip: 'rect(0 0 0 0)',
-        height: 'auto',
-        margin: 0,
-        overflow: 'hidden',
-        padding: 0,
-        position: 'absolute',
-        width: '1px',
-        whiteSpace: 'nowrap',
-    },
-}));
-
-export const ConnectedInstances = () => {
+export const ConnectedInstances: FC = () => {
     const name = useRequiredPathParam('name');
     const { application } = useApplication(name);
-    const [currentEnvironment, setCurrentEnvironment] =
-        useQueryParam('environment');
-    const availableEnvironments = new Set(
-        application?.instances.map(
-            // @ts-expect-error: the type definition here is incomplete. It
-            // should be updated as part of this project.
-            (instance) => instance.environment,
-        ),
+    const { data: applicationOverview } = useApplicationOverview(name);
+
+    const availableEnvironments = applicationOverview.environments.map(
+        (env) => env.name,
     );
-    const allEnvironmentsSorted = Array.from(availableEnvironments)
-        .sort((a, b) => a.localeCompare(b))
-        .map((env) => ({ name: env, problemsDetected: false }));
+    const allEnvironmentsSorted = Array.from(availableEnvironments).sort(
+        (a, b) => a.localeCompare(b),
+    );
+    const [currentEnvironment, setCurrentEnvironment] = useState(
+        allEnvironmentsSorted[0],
+    );
+    const { data: connectedInstances } = useConnectedInstances(
+        name,
+        currentEnvironment,
+    );
+
+    useEffect(() => {
+        if (!currentEnvironment && availableEnvironments.length > 0) {
+            setCurrentEnvironment(availableEnvironments[0]);
+        }
+    }, [JSON.stringify(availableEnvironments)]);
 
     const tableData = useMemo(() => {
         const map = ({
@@ -123,41 +62,28 @@ export const ConnectedInstances = () => {
         useConnectedInstancesTable(tableData);
 
     return (
-        <Container>
-            <EnvironmentSelectionContainer>
-                <fieldset>
-                    <legend>
-                        Select which environment to display data for. Only
-                        environments that have received traffic for this
-                        application will be shown here.
-                    </legend>
+        <Box>
+            <Box sx={{ mb: 3 }}>
+                <Box sx={{ mb: 2 }}>
+                    Select which environment to display data for. Only
+                    environments that have received traffic for this application
+                    will be shown here.
+                </Box>
+                <ToggleButtonGroup
+                    color='primary'
+                    value={currentEnvironment}
+                    exclusive
+                    onChange={(event, value) => {
+                        if (value !== null) {
+                            setCurrentEnvironment(value);
+                        }
+                    }}
+                >
                     {allEnvironmentsSorted.map((env) => {
-                        return (
-                            <label key={env.name}>
-                                {env.name}
-
-                                <ConditionallyRender
-                                    condition={env.problemsDetected}
-                                    show={
-                                        <WarningAmber titleAccess='Problems detected' />
-                                    }
-                                />
-                                <input
-                                    defaultChecked={
-                                        currentEnvironment === env.name
-                                    }
-                                    className='visually-hidden'
-                                    type='radio'
-                                    name='active-environment'
-                                    onClick={() => {
-                                        setCurrentEnvironment(env.name);
-                                    }}
-                                />
-                            </label>
-                        );
+                        return <ToggleButton value={env}>{env}</ToggleButton>;
                     })}
-                </fieldset>
-            </EnvironmentSelectionContainer>
+                </ToggleButtonGroup>
+            </Box>
             <ConnectedInstancesTable
                 loading={false}
                 headerGroups={headerGroups}
@@ -166,6 +92,6 @@ export const ConnectedInstances = () => {
                 getTableProps={getTableProps}
                 rows={rows}
             />
-        </Container>
+        </Box>
     );
 };
diff --git a/frontend/src/component/application/ConnectedInstances/useConnectedInstancesTable.tsx b/frontend/src/component/application/ConnectedInstances/useConnectedInstancesTable.tsx
index 234b1d8aa1..751ac8215e 100644
--- a/frontend/src/component/application/ConnectedInstances/useConnectedInstancesTable.tsx
+++ b/frontend/src/component/application/ConnectedInstances/useConnectedInstancesTable.tsx
@@ -14,7 +14,7 @@ export const useConnectedInstancesTable = (
     instanceData: ConnectedInstancesTableData[],
 ) => {
     const initialState = useMemo(
-        () => ({ sortBy: [{ id: 'instanceId' }] }),
+        () => ({ sortBy: [{ id: 'lastSeen', desc: true }] }),
         [],
     );
 
diff --git a/frontend/src/hooks/api/getters/useConnectedInstances/useConnectedInstances.ts b/frontend/src/hooks/api/getters/useConnectedInstances/useConnectedInstances.ts
new file mode 100644
index 0000000000..912797b28a
--- /dev/null
+++ b/frontend/src/hooks/api/getters/useConnectedInstances/useConnectedInstances.ts
@@ -0,0 +1,44 @@
+import { SWRConfiguration } from 'swr';
+import { formatApiPath } from 'utils/formatPath';
+import handleErrorResponses from '../httpErrorResponseHandler';
+import { useConditionalSWR } from '../useConditionalSWR/useConditionalSWR';
+
+type ConnectedInstancesSchema = {
+    instances: {
+        instanceId: string;
+        sdk: string;
+        clientIp: string;
+        lastSeen: string;
+    }[];
+};
+
+export const useConnectedInstances = (
+    application: string,
+    environment?: string,
+    options: SWRConfiguration = {},
+) => {
+    const path = formatApiPath(
+        `api/admin/metrics/instances/${application}/${environment}`,
+    );
+    const { data, error } = useConditionalSWR<ConnectedInstancesSchema>(
+        Boolean(environment),
+        { instances: [] },
+        path,
+        fetcher,
+        options,
+    );
+
+    return {
+        data: data || { instances: [] },
+        error,
+        loading: !error && !data,
+    };
+};
+
+const fetcher = async (path: string): Promise<ConnectedInstancesSchema> => {
+    const res = await fetch(path).then(
+        handleErrorResponses('Connected instances'),
+    );
+    const data = await res.json();
+    return data;
+};