diff --git a/keyserver/src/services/blob.js b/keyserver/src/services/blob.js
--- a/keyserver/src/services/blob.js
+++ b/keyserver/src/services/blob.js
@@ -4,12 +4,27 @@
 import { makeBlobServiceEndpointURL } from 'lib/utils/blob-service.js';
 import { getMessageForException } from 'lib/utils/errors.js';
 
-async function upload(blob: Blob, hash: string, holder: string): Promise<void> {
+async function uploadBlob(blob: Blob, hash: string): Promise<void> {
   const formData = new FormData();
   formData.append('blob_hash', hash);
   formData.append('blob_data', blob);
 
-  const assignHolderPromise = fetch(
+  const uploadBlobResponse = await fetch(
+    makeBlobServiceEndpointURL(blobService.httpEndpoints.UPLOAD_BLOB),
+    {
+      method: blobService.httpEndpoints.UPLOAD_BLOB.method,
+      body: formData,
+    },
+  );
+
+  if (!uploadBlobResponse.ok) {
+    const { status, statusText } = uploadBlobResponse;
+    throw new Error(`Payload upload failed with HTTP ${status}: ${statusText}`);
+  }
+}
+
+async function assignHolder(holder: string, hash: string): Promise<void> {
+  const assignHolderResponse = await fetch(
     makeBlobServiceEndpointURL(blobService.httpEndpoints.ASSIGN_HOLDER),
     {
       method: blobService.httpEndpoints.ASSIGN_HOLDER.method,
@@ -23,20 +38,17 @@
     },
   );
 
-  const uploadHolderPromise = fetch(
-    makeBlobServiceEndpointURL(blobService.httpEndpoints.UPLOAD_BLOB),
-    {
-      method: blobService.httpEndpoints.UPLOAD_BLOB.method,
-      body: formData,
-    },
-  );
+  if (!assignHolderResponse.ok) {
+    const { status, statusText } = assignHolderResponse;
+    throw new Error(
+      `Holder assignment failed with HTTP ${status}: ${statusText}`,
+    );
+  }
+}
 
-  let assignHolderResponse, uploadBlobResponse;
+async function upload(blob: Blob, hash: string, holder: string): Promise<void> {
   try {
-    [assignHolderResponse, uploadBlobResponse] = await Promise.all([
-      assignHolderPromise,
-      uploadHolderPromise,
-    ]);
+    await Promise.all([assignHolder(holder, hash), uploadBlob(blob, hash)]);
   } catch (e) {
     throw new Error(
       `Payload upload failed with: ${
@@ -44,18 +56,6 @@
       }`,
     );
   }
-
-  if (!assignHolderResponse.ok) {
-    const { status, statusText } = assignHolderResponse;
-    throw new Error(
-      `Holder assignment failed with HTTP ${status}: ${statusText}`,
-    );
-  }
-
-  if (!uploadBlobResponse.ok) {
-    const { status, statusText } = uploadBlobResponse;
-    throw new Error(`Payload upload failed with HTTP ${status}: ${statusText}`);
-  }
 }
 
-export { upload };
+export { upload, uploadBlob, assignHolder };