stream response for progressive rendering

also: deploy when pushing "straging" branch along with "develop"

.github/workflows/deploy-staging.yml

@@ -2,7 +2,7 @@ name: Publish to dockerhub and perform a deploy on cloud run
 
 on:
   push:
-    branches: ["develop"]
+    branches: ["develop", "staging"]
 
 jobs:
   build-and-push-image:

app.js

@@ -45,16 +45,16 @@ app.get("*", async (req, res) => {
         .send("upstream server did not respond with a valid status code");
     }
 
-    const processedImage = await sharp(data)
-      .rotate()
-      .resize({ width, height })
-      .toFormat(format, { quality });
-
-    return res
+    res
       .set("Cache-Control", "public, max-age=15552000")
       .set("Vary", "Accept")
-      .type(`image/${format}`)
-      .send(await processedImage.toBuffer());
+      .type(`image/${format}`);
+
+    sharp(data)
+      .rotate()
+      .resize({ width, height })
+      .toFormat(format, { quality, progressive: true })
+      .pipe(res);
   } catch (e) {
     return res.status(500).send(JSON.stringify(e));
   }