diff --git a/lib/tasks/db.rake b/lib/tasks/db.rake
index 14b2eb4e20..027483f39d 100644
--- a/lib/tasks/db.rake
+++ b/lib/tasks/db.rake
@@ -66,6 +66,71 @@ task 'db:rollback' => ['environment', 'set_locale'] do |_, args|
   Rake::Task['db:_dump'].invoke
 end
 
+# our optimized version of multisite migrate, we have many sites and we have seeds
+# this ensures we can run migrations concurrently to save huge amounts of time
+Rake::Task['multisite:migrate'].clear
+
+task 'multisite:migrate' => ['db:load_config', 'environment', 'set_locale'] do |_, args|
+  if ENV["RAILS_ENV"] != "production"
+    raise "Multisite migrate is only supported in production"
+  end
+
+  concurrency = (ENV['MIGRATE_CONCURRENCY'].presence || "20").to_i
+
+  puts "Multisite migrator is running using #{concurrency} threads"
+  puts
+
+  queue = Queue.new
+  exceptions = Queue.new
+
+  RailsMultisite::ConnectionManagement.each_connection do |db|
+    queue << db
+  end
+
+  concurrency.times { queue << :done }
+
+  SeedFu.quiet = true
+
+  (1..concurrency).map do
+    Thread.new {
+      while true
+        db = queue.pop
+        break if db == :done
+
+        RailsMultisite::ConnectionManagement.with_connection(db) do
+          begin
+            puts "Migrating #{db}"
+            ActiveRecord::Tasks::DatabaseTasks.migrate
+            SeedFu.seed(DiscoursePluginRegistry.seed_paths)
+            if !Discourse.skip_post_deployment_migrations? && ENV['SKIP_OPTIMIZE_ICONS'] != '1'
+              SiteIconManager.ensure_optimized!
+            end
+          rescue => e
+            exceptions << [db, e]
+          end
+        end
+      end
+    }
+  end.each(&:join)
+
+  if exceptions.length > 0
+    STDERR.puts
+    STDERR.puts "-" * 80
+    STDERR.puts "#{exceptions.length} migrations failed!"
+    while !exceptions.empty?
+      db, e = exceptions.pop
+      STDERR.puts
+      STDERR.puts "Failed to migrate #{db}"
+      STDERR.puts e.inspect
+      STDERR.puts e.backtrace
+      STDERR.puts
+    end
+    exit 1
+  end
+
+  Rake::Task['db:_dump'].invoke
+end
+
 # we need to run seed_fu every time we run rake db:migrate
 task 'db:migrate' => ['load_config', 'environment', 'set_locale'] do |_, args|