diff --git a/.github/workflows/future_proof.yml b/.github/workflows/future_proof.yml
index a3b3370e..822fe90c 100644
--- a/.github/workflows/future_proof.yml
+++ b/.github/workflows/future_proof.yml
@@ -17,8 +17,9 @@ jobs:
       fail-fast: false
       matrix:
         ruby-version:
-          - '3.2' # Latest ruby 3.2.x
+          - '3.2' # Latest ruby 3.2.x (no longer used, but preserve the option to rollback)
           - '3.3' # Latest ruby 3.3.x
+          - '3.4' # Latest ruby 3.4.x
 
     name: "Ruby ${{ matrix.ruby-version }} Smoke Tests"
 
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index bdb4bcd4..625f9ac6 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -16,7 +16,7 @@ jobs:
       fail-fast: false
       matrix:
         ruby-version:
-          - '3.2.8'
+          - '3.3.9'
         test-group:
           - "[a-b]"
           - "[c]"
@@ -94,7 +94,7 @@ jobs:
       fail-fast: false
       matrix:
         ruby-version:
-          - '3.2.8'
+          - '3.3.9'
         test-group:
           - "[a-z]"
 
diff --git a/.ruby-version b/.ruby-version
index f092941a..3b47f2e4 100644
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-3.2.8
+3.3.9
diff --git a/Gemfile b/Gemfile
index 51bb7e65..4637ec2d 100644
--- a/Gemfile
+++ b/Gemfile
@@ -11,9 +11,6 @@ gem 'rails', '~> 7.2.2', '>= 7.2.2.2'
 # Fixes uninitialized constant ActiveSupport::LoggerThreadSafeLevel::Logger on Rails 7.0x
 # and earlier. See https://github.com/rails/rails/issues/54260.
 gem 'concurrent-ruby', '1.3.4'
-# Use old psych for YAML on Ruby 3.1 until we move to Rails 7.0.4
-# so that we can continue to use aliases in config/locales/en.yml
-# cf. https://stackoverflow.com/questions/71191685/visit-psych-nodes-alias-unknown-alias-default-psychbadalias
 gem 'psych', '4.0.4' # Exactly match the version on Ruby 3.1
 gem 'stringio', '3.1.1' # psych dependency: exactly match the default version on Ruby 3.3
 
@@ -62,7 +59,7 @@ gem 'will_paginate'
 # gem 'capistrano-rails', group: :development
 
 # net-imap (via ndr_error) requires date. Puma needs us to stick to the ruby default version.
-gem 'date', '3.1.3' # Lock to Ruby 3.0 version of gem for live service
+gem 'date', '3.3.4' # Lock to Ruby 3.3 version of gem for live service
 
 gem 'ndr_authenticate', '~> 0.3', '>= 0.3.3'
 gem 'ndr_error', '~> 2.0'
diff --git a/Gemfile.lock b/Gemfile.lock
index 222c61f7..a6d0ce8b 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -149,7 +149,7 @@ GEM
     crass (1.0.6)
     csv (3.3.0)
     daemons (1.4.1)
-    date (3.1.3)
+    date (3.3.4)
     delayed_job (4.1.13)
       activesupport (>= 3.0, < 9.0)
     delayed_job_active_record (4.1.11)
@@ -273,7 +273,7 @@ GEM
       net-ldap
       rails (>= 7.0, < 7.3)
       yubikey
-    ndr_dev_support (7.3.3)
+    ndr_dev_support (7.3.4)
       activesupport (>= 6.1, < 8.1)
       brakeman (>= 4.7.1)
       bundler-audit
@@ -605,7 +605,7 @@ DEPENDENCIES
   coffee-rails
   concurrent-ruby (= 1.3.4)
   daemons
-  date (= 3.1.3)
+  date (= 3.3.4)
   delayed_job (~> 4.1)
   delayed_job_active_record
   devise (~> 4.7, >= 4.7.1)
@@ -656,4 +656,4 @@ DEPENDENCIES
   will_paginate
 
 BUNDLED WITH
-   2.4.19
+   2.5.22
diff --git a/README.md b/README.md
index 3dc1e3da..23df3004 100644
--- a/README.md
+++ b/README.md
@@ -1,14 +1,14 @@
 # Data Management System [![Build Status](https://github.com/publichealthengland/data_management_system/workflows/Test/badge.svg)](https://github.com/publichealthengland/data_management_system/actions?query=workflow%3Atest)
 
-* Rails version 6.1.7
-* Ruby version is 3.0.4
+* Rails version 7.2.x
+* Ruby version is 3.3.x
 
 ## System dependencies
 
-  * ndr_dev_support ~> 6.0
+  * ndr_dev_support '~> 7.0'
   * ndr_error '~> 2.0'
   * ndr_support '~> 5.9'
-  * ndr_ui (3.3.1)
+  * ndr_ui '~> 3.3'
 
 ## Configuration
 
diff --git a/app/models/project_dataset_level.rb b/app/models/project_dataset_level.rb
index 5caa75ca..4d431b49 100644
--- a/app/models/project_dataset_level.rb
+++ b/app/models/project_dataset_level.rb
@@ -12,7 +12,7 @@ class ProjectDatasetLevel < ApplicationRecord
   validates :status, uniqueness: { scope: %i[access_level_id project_dataset_id] },
                      if: proc { |pdl| %w[request approved renewable].include?(pdl.status) }
 
-  enum status: { request: 1, approved: 2, rejected: 3, renewable: 4, closed: 5 }
+  enum :status, { request: 1, approved: 2, rejected: 3, renewable: 4, closed: 5 }
 
   scope :same_access_level_levels, lambda { |pdl|
     where(project_dataset_id: pdl.project_dataset_id, access_level_id: pdl.access_level_id).
diff --git a/config/deploy.rb b/config/deploy.rb
index a6c6055e..b046cf62 100644
--- a/config/deploy.rb
+++ b/config/deploy.rb
@@ -220,15 +220,16 @@
     # deploying user, rather than the application user.
     # You can override the path using e.g. set :pg_conf_path, '/usr/pgsql-9.5/bin/pg_config'
     # otherwise the latest installed version will be used.
+    # Note that the relevant postgresql-devel package is required, not just postgresql
     run <<~SHELL
       set -e;
       cd #{release_path};
       pg_conf_path="#{fetch(:pg_conf_path, '')}";
       if [ -z "$pg_conf_path" ]; then
-        pg_conf_path=`ls -1d /usr/pgsql-{9,[1-8]*}/bin/pg_config 2> /dev/null | tail -1`;
+        pg_conf_path=`ls -1d /usr/pgsql-{9*,[1-8]*}/include 2> /dev/null | sed -e 's:/include$:/bin/pg_config:' | tail -1`;
       fi;
       if [ -n "$pg_conf_path" ]; then
-        echo Using pg_conf_path=\"$pg_conf_path\";
+        echo Using pg_conf_path=\\"$pg_conf_path\\";
         bundle config --local build.pg --with-pg-config="$pg_conf_path";
       fi
     SHELL
diff --git a/config/deployments.yml b/config/deployments.yml
index 9a145de6..005d63f0 100644
--- a/config/deployments.yml
+++ b/config/deployments.yml
@@ -4,7 +4,7 @@
 ---
 beta:
   branch: 'main'
-  ruby: 3.2.8
+  ruby: 3.3.9
 live:
   branch: 'main'
-  ruby: 3.2.8
+  ruby: 3.3.9
diff --git a/lib/tasks/seed_cas_dataset.rake b/lib/tasks/seed_cas_dataset.rake
index c632383d..0f512c6f 100644
--- a/lib/tasks/seed_cas_dataset.rake
+++ b/lib/tasks/seed_cas_dataset.rake
@@ -21,7 +21,7 @@ namespace :cas do
     fname = Rails.root.join('lib', 'tasks', 'xsd', 'nodes_cas.yml')
 
     Node.transaction do
-      YAML.safe_load(File.open(fname), [Symbol]).each do |row|
+      YAML.safe_load(File.open(fname), permitted_classes: [Symbol]).each do |row|
         version = row['dataset_version']
         dataset = row['name']
         print "Building nodes for #{version}\n"
diff --git a/lib/tasks/xsd_seed.rake b/lib/tasks/xsd_seed.rake
index 48637901..69d7304f 100644
--- a/lib/tasks/xsd_seed.rake
+++ b/lib/tasks/xsd_seed.rake
@@ -44,7 +44,7 @@ namespace :xsd do
     fname = Rails.root.join('lib', 'tasks', 'xsd', 'nodes.yml')
 
     Node.transaction do
-      YAML.safe_load(File.open(fname), [Symbol]).each do |row|
+      YAML.safe_load(File.open(fname), permitted_classes: [Symbol]).each do |row|
         version = row['dataset_version']
         dataset = row['name']
         print "Building nodes for #{version}\n"
@@ -103,7 +103,7 @@ namespace :xsd do
     fname = Rails.root.join('lib', 'tasks', 'xsd', 'xml_types.yml')
     before = XmlType.count
     XmlType.transaction do
-      YAML.safe_load(File.open(fname), [Symbol]).each do |row|
+      YAML.safe_load(File.open(fname), permitted_classes: [Symbol]).each do |row|
         row.delete(:pattern) if row[:pattern].blank?
         row.delete(:decimal_places) if row[:decimal_places].blank?
         ignore = %w[xml_attribute_for_value enumeration_values attribute_names]
@@ -142,7 +142,7 @@ namespace :xsd do
     fname = Rails.root.join('lib', 'tasks', 'xsd', 'datasets.yml')
     before = Dataset.count
     Dataset.transaction do
-      YAML.safe_load(File.open(fname), [Symbol]).each_value do |row|
+      YAML.safe_load(File.open(fname), permitted_classes: [Symbol]).each_value do |row|
         d = Dataset.new(row)
         d.dataset_type = DatasetType.find_by(name: 'XML Schema')
         d.save!(validate: false)
@@ -157,7 +157,7 @@ namespace :xsd do
     fname = Rails.root.join('lib', 'tasks', 'xsd', 'dataset_versions.yml')
     before = DatasetVersion.count
     DatasetVersion.transaction do
-      YAML.safe_load(File.open(fname), [Symbol]).each_value do |row|
+      YAML.safe_load(File.open(fname), permitted_classes: [Symbol]).each_value do |row|
         d = DatasetVersion.new(row.except('dataset'))
         d.dataset = Dataset.find_by(name: row['dataset'])
         d.save!
@@ -172,7 +172,7 @@ namespace :xsd do
     attrs = Rails.root.join('lib', 'tasks', 'xsd', 'xml_attributes.yml')
     counter = 0
     Nodes::DataItem.transaction do
-      YAML.safe_load(File.open(attrs), [Symbol]).each_value do |row|
+      YAML.safe_load(File.open(attrs), permitted_classes: [Symbol]).each_value do |row|
         x = XmlAttribute.new(row)
         x.save!
         counter += 1
@@ -187,7 +187,7 @@ namespace :xsd do
     fname = Rails.root.join('lib', 'tasks', 'xsd', 'categories.yml')
     before = Category.count
     Category.transaction do
-      YAML.safe_load(File.open(fname), [Symbol]).each_value do |row|
+      YAML.safe_load(File.open(fname), permitted_classes: [Symbol]).each_value do |row|
         ignored_fields = %w[dataset_name dataset_version]
         e = Category.new(row.except(*ignored_fields))
         e.dataset_version = version_for_dataset(row['dataset_name'], row['dataset_version'])
@@ -203,7 +203,7 @@ namespace :xsd do
     fname = Rails.root.join('lib', 'tasks', 'xsd', 'data_dictionary_element.yml')
     before = DataDictionaryElement.count
     DataDictionaryElement.transaction do
-      YAML.safe_load(File.open(fname), [Symbol]).each do |row|
+      YAML.safe_load(File.open(fname), permitted_classes: [Symbol]).each do |row|
         dde = DataDictionaryElement.new(row.except('xml_type'))
         dde.xml_type = XmlType.find_by(name: row['xml_type']) unless row['xml_type'].nil?
         dde.save!
@@ -238,7 +238,7 @@ namespace :xsd do
   # Task for updating fixtures
   task upp: :environment do
     fname = Rails.root.join('lib', 'tasks', 'xsd', 'nodes.yml')
-    x = YAML.safe_load(File.open(fname), [Symbol]).each do |row|
+    x = YAML.safe_load(File.open(fname), permitted_classes: [Symbol]).each do |row|
       child_up(row)
     end
     puts x.to_yaml
@@ -373,7 +373,7 @@ namespace :xsd do
     fname = Rails.root.join('lib', 'tasks', 'xsd', 'categories.yml')
     before = Category.count
     Category.transaction do
-      YAML.safe_load(File.open(fname), [Symbol]).each_value do |row|
+      YAML.safe_load(File.open(fname), permitted_classes: [Symbol]).each_value do |row|
         next unless row['dataset_version'] == '4-1-1'
 
         ignored_fields = %w[dataset_name dataset_version]
@@ -392,7 +392,7 @@ namespace :xsd do
     fname = Rails.root.join('lib', 'tasks', 'xsd', 'nodes.yml')
 
     Node.transaction do
-      YAML.safe_load(File.open(fname), [Symbol]).each do |row|
+      YAML.safe_load(File.open(fname), permitted_classes: [Symbol]).each do |row|
         version = row['dataset_version']
         next unless version == '4-1-1'
 
@@ -457,7 +457,7 @@ namespace :xsd do
 
       fname = Rails.root.join('lib', 'tasks', 'xsd', 'COSDv9.0.1.yml')
 
-      YAML.safe_load(File.open(fname), [Symbol]).each do |row|
+      YAML.safe_load(File.open(fname), permitted_classes: [Symbol]).each do |row|
         print "Building nodes for #{v9_0_1.semver_version}\n"
         node = build_node(row, v9_0_1)
         if row['children'].present?
diff --git a/vendor/cache/date-3.1.3.gem b/vendor/cache/date-3.1.3.gem
deleted file mode 100644
index 987b8e29..00000000
Binary files a/vendor/cache/date-3.1.3.gem and /dev/null differ
diff --git a/vendor/cache/date-3.3.4.gem b/vendor/cache/date-3.3.4.gem
new file mode 100644
index 00000000..712d2c03
Binary files /dev/null and b/vendor/cache/date-3.3.4.gem differ
diff --git a/vendor/cache/ndr_dev_support-7.3.3.gem b/vendor/cache/ndr_dev_support-7.3.3.gem
deleted file mode 100644
index 1601aae3..00000000
Binary files a/vendor/cache/ndr_dev_support-7.3.3.gem and /dev/null differ
diff --git a/vendor/cache/ndr_dev_support-7.3.4.gem b/vendor/cache/ndr_dev_support-7.3.4.gem
new file mode 100644
index 00000000..6fa2ff76
Binary files /dev/null and b/vendor/cache/ndr_dev_support-7.3.4.gem differ
diff --git a/vendor/rbenv/cache/ruby-3.2.8.tar.gz b/vendor/rbenv/cache/ruby-3.3.9.tar.gz
similarity index 66%
rename from vendor/rbenv/cache/ruby-3.2.8.tar.gz
rename to vendor/rbenv/cache/ruby-3.3.9.tar.gz
index 6fdc990e..7d4bd494 100644
Binary files a/vendor/rbenv/cache/ruby-3.2.8.tar.gz and b/vendor/rbenv/cache/ruby-3.3.9.tar.gz differ
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index 1e1f6cd8..cfb20435 100644
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diff --git a/vendor/rbenv/ruby-build.tar.gz b/vendor/rbenv/ruby-build.tar.gz
index db626ed4..4e148042 100644
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