diff --git a/apps/backend/src/routers/users.ts b/apps/backend/src/routers/users.ts
index 73817a84e..83cd38333 100644
--- a/apps/backend/src/routers/users.ts
+++ b/apps/backend/src/routers/users.ts
@@ -8,6 +8,8 @@ import { mangleDupliateScheduleNames } from 'src/lib/formatting';
 import { RDS } from 'src/lib/rds';
 import { TRPCError } from '@trpc/server';
 import { procedure, router } from '../trpc';
+import { ddbClient } from '$db/ddb';
+
 
 const userInputSchema = type([{ userId: 'string' }, '|', { googleId: 'string' }]);
 
@@ -52,8 +54,17 @@ const usersRouter = router({
                 // Mangle duplicate schedule names
                 data.userData.schedules = mangleDupliateScheduleNames(data.userData.schedules);
 
-                await RDS.upsertGuestUserData(db, data)
-                    .catch((error) => console.error('Failed to upsert user data:', error));
+                // Await both, but only throw if RDS save fails.
+                const results = await Promise.allSettled([
+                    ddbClient.insertItem(data)
+                        .catch((error) => console.error('DDB Failed to save user data:', error)),
+                    RDS.upsertGuestUserData(db, data)
+                        .catch((error) => console.error('RDS Failed to upsert user data:', error))
+                ]);
+
+                if (results[1].status === 'rejected') {
+                    throw results[1].reason;
+                }
             }
         ),
 });