diff --git a/.circleci/config.yml b/.circleci/config.yml
index 0f9aac9..1ce0e5a 100755
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -1,19 +1,12 @@
 version: 2.1
 
-# ENV VARS required
-# AZURE_SP           - service principal given the Contributor role on the Azure Container Registry
-# AZURE_SP_PASSWORD  - service principal password
-# AZURE_SP_TENANT    - tenant of servie principal
-# AZURE_SUBSCRIPTION - name of Azure subscription with the container registry
-# AZURE_ACR_REGISTRY - name of Azure Container Registry
-
 orbs:
   azure-cli: circleci/azure-cli@1.2.0
 
 aliases:
   - defaults: &defaults
       docker:
-        - image: cimg/node:22.17
+        - image: cimg/ruby:3.1.7-node
       working_directory: ~/code
   - &restore-repo-cache
       key: socket-goodcity-repo-{{ .Environment.CIRCLE_SHA1 }}
@@ -55,8 +48,6 @@ jobs:
       
   deployment:
     <<: *defaults
-    docker:
-      - image: cimg/ruby:2.7.8-node
     steps:
       - restore_cache: *restore-repo-cache
       - restore_cache: *restore-yarn-cache
@@ -65,16 +56,6 @@ jobs:
       - run: |
           ([ "$CIRCLE_BRANCH" == "live" ] && bundle exec cap production deploy) || ([ "$CIRCLE_BRANCH" == "master" ] && bundle exec cap staging deploy)
 
-  build-and-deploy-docker-image:
-    executor: azure-cli/default
-    working_directory: ~/code
-    steps:
-      - restore_cache: *restore-repo-cache
-      - azure-cli/install
-      - azure-cli/login-with-service-principal
-      - run: az account set --subscription $AZURE_SUBSCRIPTION
-      - run: az acr build --registry $AZURE_ACR_REGISTRY --image socketio:$CIRCLE_BRANCH .
-
 workflows:
     build-and-deploy:
       jobs:
@@ -88,9 +69,3 @@ workflows:
             filters:
               branches:
                 only: /^(master|live)$/
-        # - build-and-deploy-docker-image:
-        #     requires:
-        #       - checkout_code
-        #     filters:
-        #       branches:
-        #         only: /^(master|live)$/
diff --git a/.ruby-version b/.ruby-version
index c0013a8..434c481 100755
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-ruby-2.7.3
+ruby-3.1.7
diff --git a/Gemfile.lock b/Gemfile.lock
index b8365ab..1438646 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -13,7 +13,7 @@ GEM
     capistrano-nvm (0.0.7)
       capistrano (~> 3.1)
     concurrent-ruby (1.3.6)
-    ed25519 (1.3.0)
+    ed25519 (1.4.0)
     i18n (1.14.8)
       concurrent-ruby (~> 1.0)
     logger (1.7.0)
diff --git a/config/deploy/preview.rb b/config/deploy/preview.rb
deleted file mode 100644
index 2c741a1..0000000
--- a/config/deploy/preview.rb
+++ /dev/null
@@ -1,2 +0,0 @@
-server 'socket-staging.goodcity.hk:59207', user: 'deployer', roles: %w{web}
-set :deploy_to, '/opt/node/socket.io-webservice-preview'
\ No newline at end of file