diff --git a/Gemfile b/Gemfile
index 21725c2..d2c8f93 100644
--- a/Gemfile
+++ b/Gemfile
@@ -18,6 +18,6 @@ group :test do
   gem 'et_test_helpers', git: 'https://github.com/hmcts/et_test_helpers.git', tag: 'v1.3.2'
 end
 group :development, :test do
-  gem "webrick", "~> 1.8"
+  gem "puma"
 end
 
diff --git a/Gemfile.lock b/Gemfile.lock
index d51dfa6..0754990 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -16,7 +16,7 @@ PATH
   specs:
     et_gds_design_system (5.4.3)
       govuk_design_system_formbuilder (~> 4.0)
-      rack (< 3.0.0)
+      rack
       rails (>= 6.0)
       typhoeus (~> 1.4)
       webpacker (~> 5.0)
@@ -184,17 +184,19 @@ GEM
     psych (5.1.2)
       stringio
     public_suffix (5.0.5)
+    puma (6.4.2)
+      nio4r (~> 2.0)
     racc (1.7.3)
-    rack (2.2.9)
+    rack (3.0.10)
     rack-proxy (0.7.7)
       rack
-    rack-session (1.0.2)
-      rack (< 3)
+    rack-session (2.0.0)
+      rack (>= 3.0.0)
     rack-test (2.1.0)
       rack (>= 1.3)
-    rackup (1.0.0)
-      rack (< 3)
-      webrick
+    rackup (2.1.0)
+      rack (>= 3)
+      webrick (~> 1.8)
     rails (7.1.3.2)
       actioncable (= 7.1.3.2)
       actionmailbox (= 7.1.3.2)
@@ -299,10 +301,10 @@ DEPENDENCIES
   dotenv-rails (~> 3.1)
   et_gds_design_system!
   et_test_helpers!
+  puma
   rspec-rails (~> 6.0)
   selenium-webdriver (~> 4.9)
   site_prism (~> 5.0)
-  webrick (~> 1.8)
 
 BUNDLED WITH
    2.1.4
diff --git a/app/controllers/et_gds_design_system/blobs_controller.rb b/app/controllers/et_gds_design_system/blobs_controller.rb
index ef4a3a1..b216699 100644
--- a/app/controllers/et_gds_design_system/blobs_controller.rb
+++ b/app/controllers/et_gds_design_system/blobs_controller.rb
@@ -4,6 +4,7 @@ class BlobsController < ::ApplicationController
 
     def create
       service = Api::CreateBlobService.new
+      request.body.rewind
       response = service.call(request.body.read, headers: request.headers)
       respond_to do |format|
         if response.success?
diff --git a/app/javascript/components/DropzoneUploader.js b/app/javascript/components/DropzoneUploader.js
index 80ac21a..cc38ceb 100644
--- a/app/javascript/components/DropzoneUploader.js
+++ b/app/javascript/components/DropzoneUploader.js
@@ -99,6 +99,7 @@ const initDropzone = (node, type, acceptedFiles, attributeName, createBlobUrl) =
         if (provider === 'azure') {
           const send = xhr.send;
           xhr.send = function () {
+            debugger
             send.call(xhr, file);
             xhr.send = send;
           };
diff --git a/et_gds_design_system.gemspec b/et_gds_design_system.gemspec
index f145f97..0ecdcb7 100644
--- a/et_gds_design_system.gemspec
+++ b/et_gds_design_system.gemspec
@@ -20,7 +20,7 @@ Gem::Specification.new do |spec|
   spec.add_dependency 'rails', '>= 6.0'
   spec.add_dependency 'typhoeus', '~> 1.4'
   spec.add_dependency 'webpacker', '~> 5.0'
-  spec.add_dependency 'rack', '< 3.0.0'
+  spec.add_dependency 'rack'
 
   spec.add_development_dependency 'activerecord-nulldb-adapter', '~> 1.0'
   spec.add_development_dependency 'capybara', '~> 3'
diff --git a/spec/support/capybara.rb b/spec/support/capybara.rb
index b5ff1a2..599e6fa 100644
--- a/spec/support/capybara.rb
+++ b/spec/support/capybara.rb
@@ -54,5 +54,5 @@
 end
 
 Capybara.always_include_port = true
-Capybara.server = :webrick
+Capybara.server = :puma
 Capybara.save_path = File.absolute_path(File.join('..', '..', 'tmp', 'capybara'), __dir__)