diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 8b9e672..60d3993 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -18,12 +18,84 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
+    - name: Preparing timer
+      id: timer_start
+      run: |
+        echo "DATE_START=$(date +'%Y-%m-%d %H:%M:%S')" >> $GITHUB_OUTPUT
+        echo "TIMESTAMP_START=$(date +'%s')" >> $GITHUB_OUTPUT
+    - name: "Slack notification: IN PROGRESS"
+      id: slack
+      uses: slackapi/slack-github-action@v1.24.0
+      with:
+        channel-id: 'C068A06PV43'
+        payload: |
+          {
+            "text": "CI Build Status for playground-matrix: IN PROGRESS\n${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}",
+            "blocks": [
+              {
+                "type": "header",
+                "text": {
+                  "type": "plain_text",
+                  "text": ":runner: CI Build Status for playground-matrix"
+                }
+              },
+              {
+                "type": "section",
+                "fields": [
+                  {
+                    "type": "mrkdwn",
+                    "text": "*Start:*\n${{ steps.timer_start.outputs.DATE_START }}"
+                  },
+                  {
+                    "type": "mrkdwn",
+                    "text": "*End:*\n--"
+                  }
+                ]
+              },
+              {
+                "type": "section",
+                "fields": [
+                  {
+                    "type": "mrkdwn",
+                    "text": "*Status:* IN PROGRESS"
+                  },
+                  {
+                    "type": "mrkdwn",
+                    "text": ":timer_clock: --"
+                  }
+                ]
+              },
+              {
+                "type": "section",
+                "text": {
+                  "type": "mrkdwn",
+                  "text": "*PR:* ${{ github.event.pull_request.html_url || github.event.head_commit.url }}"
+                }
+              },
+              {
+                "type": "section",
+                "text": {
+                  "type": "mrkdwn",
+                  "text": "*Build:* ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}"
+                }
+              }
+            ]
+          }
+      env:
+        SLACK_BOT_TOKEN: ${{ secrets.SLACK_BOT_TOKEN }}
     - uses: actions/checkout@v3
-    - uses: php-actions/composer@v6
+    - name: Run php-actions/composer@v6
+      uses: php-actions/composer@v6
+      with:
+        php_version: "8.2"
+        php_extensions: intl
+        version: 2.x
     - uses: php-actions/phpunit@v3
       env:
         XDEBUG_MODE: coverage
       with:
+        version: "10.1"
+        php_version: "8.2"
         php_extensions: xdebug
         coverage_clover: clover.xml
         coverage_text: true
@@ -40,3 +112,133 @@ jobs:
         github_token: ${{ secrets.GITHUB_TOKEN }}
         user_name: 'github-actions[bot]'
         user_email: 'github-actions[bot]@users.noreply.github.com'
+    - name: Stopping timer
+      if: ${{ !cancelled() }}
+      id: timer_end
+      env:
+        TIMESTAMP_START: ${{ steps.timer_start.outputs.TIMESTAMP_START }}
+      run: |
+        echo "DATE_END=$(date +'%Y-%m-%d %H:%M:%S')" >> $GITHUB_OUTPUT
+        echo "DURATION_PHRASE=$(($(date +'%s')-$TIMESTAMP_START)) seconds" >> $GITHUB_OUTPUT
+    - name: "Slack notification: Done"
+      uses: slackapi/slack-github-action@v1.24.0
+      with:
+        channel-id: 'C068A06PV43'
+        update-ts: ${{ steps.slack.outputs.ts }}
+        payload: |
+          {
+            "text": "CI Build Status for playground-matrix: DONE\n${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}",
+            "blocks": [
+              {
+                "type": "header",
+                "text": {
+                  "type": "plain_text",
+                  "text": ":white_check_mark: CI Build Status for playground-matrix"
+                }
+              },
+              {
+                "type": "section",
+                "fields": [
+                  {
+                    "type": "mrkdwn",
+                    "text": "*Start:*\n${{ steps.timer_start.outputs.DATE_START }}"
+                  },
+                  {
+                    "type": "mrkdwn",
+                    "text": "*End:*\n${{ steps.timer_end.outputs.DATE_END }}"
+                  }
+                ]
+              },
+              {
+                "type": "section",
+                "fields": [
+                  {
+                    "type": "mrkdwn",
+                    "text": "*Status:* Success"
+                  },
+                  {
+                    "type": "mrkdwn",
+                    "text": ":timer_clock: ${{ steps.timer_end.outputs.DURATION_PHRASE }}"
+                  }
+                ]
+              },
+              {
+                "type": "section",
+                "text": {
+                  "type": "mrkdwn",
+                  "text": "*PR:* ${{ github.event.pull_request.html_url || github.event.head_commit.url }}"
+                }
+              },
+              {
+                "type": "section",
+                "text": {
+                  "type": "mrkdwn",
+                  "text": "*Build:* ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}"
+                }
+              }
+            ]
+          }
+      env:
+        SLACK_BOT_TOKEN: ${{ secrets.SLACK_BOT_TOKEN }}
+    - name: "Send a notification for failures"
+      if: ${{ failure() }}
+      uses: slackapi/slack-github-action@v1.24.0
+      with:
+        channel-id: 'C068A06PV43'
+        update-ts: ${{ steps.slack.outputs.ts }}
+        payload: |
+          {
+            "text": "CI Build Status for playground-matrix: FAILED\n${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}",
+            "blocks": [
+              {
+                "type": "header",
+                "text": {
+                  "type": "plain_text",
+                  "text": ":warning: CI Build Status for playground-matrix"
+                }
+              },
+              {
+                "type": "section",
+                "fields": [
+                  {
+                    "type": "mrkdwn",
+                    "text": "*Start:*\n${{ steps.timer_start.outputs.DATE_START }}"
+                  },
+                  {
+                    "type": "mrkdwn",
+                    "text": "*End:*\n${{ steps.timer_end.outputs.DATE_END }}"
+                  }
+                ]
+              },
+              {
+                "type": "section",
+                "fields": [
+                  {
+                    "type": "mrkdwn",
+                    "text": "*Status:* FAILED"
+                  },
+                  {
+                    "type": "mrkdwn",
+                    "text": ":timer_clock: ${{ steps.timer_end.outputs.DURATION_PHRASE }}"
+                  }
+                ]
+              },
+              {
+                "type": "section",
+                "text": {
+                  "type": "mrkdwn",
+                  "text": "*PR:* ${{ github.event.pull_request.html_url || github.event.head_commit.url }}"
+                }
+              },
+              {
+                "type": "section",
+                "text": {
+                  "type": "mrkdwn",
+                  "text": "*Build:* ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}"
+                }
+              }
+            ]
+          }
+      env:
+        SLACK_BOT_TOKEN: ${{ secrets.SLACK_BOT_TOKEN }}
+