diff --git a/core/file-service/src/main/scala/edu/uci/ics/texera/service/resource/DatasetResource.scala b/core/file-service/src/main/scala/edu/uci/ics/texera/service/resource/DatasetResource.scala
index 914e71ce5f2..b9dd00dbfd6 100644
--- a/core/file-service/src/main/scala/edu/uci/ics/texera/service/resource/DatasetResource.scala
+++ b/core/file-service/src/main/scala/edu/uci/ics/texera/service/resource/DatasetResource.scala
@@ -466,6 +466,7 @@ class DatasetResource {
       @PathParam("did") did: Integer,
       @QueryParam("filePath") encodedFilePath: String,
       @QueryParam("message") message: String,
+      @DefaultValue("true") @QueryParam("useMultipartUpload") useMultipartUpload: Boolean,
       fileStream: InputStream,
       @Context headers: HttpHeaders,
       @Auth user: SessionUser
@@ -486,74 +487,82 @@ class DatasetResource {
         repoName = dataset.getRepositoryName
         filePath = URLDecoder.decode(encodedFilePath, StandardCharsets.UTF_8.name)
 
-        // ---------- decide part-size & number-of-parts ----------
-        val declaredLen = Option(headers.getHeaderString(HttpHeaders.CONTENT_LENGTH)).map(_.toLong)
-        var partSize = StorageConfig.s3MultipartUploadPartSize
+        if (useMultipartUpload) {
+          // ---------- decide part-size & number-of-parts ----------
+          val declaredLen = Option(headers.getHeaderString(HttpHeaders.CONTENT_LENGTH)).map(_.toLong)
+          var partSize = StorageConfig.s3MultipartUploadPartSize
+
+          declaredLen.foreach { ln =>
+            val needed = ((ln + partSize - 1) / partSize).toInt
+            if (needed > MAXIMUM_NUM_OF_MULTIPART_S3_PARTS)
+              partSize = math.max(
+                MINIMUM_NUM_OF_MULTIPART_S3_PART,
+                ln / (MAXIMUM_NUM_OF_MULTIPART_S3_PARTS - 1)
+              )
+          }
 
-        declaredLen.foreach { ln =>
-          val needed = ((ln + partSize - 1) / partSize).toInt
-          if (needed > MAXIMUM_NUM_OF_MULTIPART_S3_PARTS)
-            partSize = math.max(
-              MINIMUM_NUM_OF_MULTIPART_S3_PART,
-              ln / (MAXIMUM_NUM_OF_MULTIPART_S3_PARTS - 1)
-            )
-        }
+          val expectedParts = declaredLen
+            .map(ln =>
+              ((ln + partSize - 1) / partSize).toInt + 1
+            ) // "+1" for the last (possibly small) part
+            .getOrElse(MAXIMUM_NUM_OF_MULTIPART_S3_PARTS)
+
+          // ---------- ask LakeFS for presigned URLs ----------
+          val presign = LakeFSStorageClient
+            .initiatePresignedMultipartUploads(repoName, filePath, expectedParts)
+          uploadId = presign.getUploadId
+          val presignedUrls = presign.getPresignedUrls.asScala.iterator
+          physicalAddress = presign.getPhysicalAddress
+
+          // ---------- stream & upload parts ----------
+          /*
+          1. Reads the input stream in chunks of 'partSize' bytes by stacking them in a buffer
+          2. Uploads each chunk (part) using a presigned URL
+          3. Tracks each part number and ETag returned from S3
+          4. After all parts are uploaded, completes the multipart upload
+           */
+          val buf = new Array[Byte](partSize.toInt)
+          var buffered = 0
+          var partNumber = 1
+          val completedParts = ListBuffer[(Int, String)]()
+
+          @inline def flush(): Unit = {
+            if (buffered == 0) return
+            if (!presignedUrls.hasNext)
+              throw new WebApplicationException("Ran out of presigned part URLs – ask for more parts")
+
+            val etag = put(buf, buffered, presignedUrls.next(), partNumber)
+            completedParts += ((partNumber, etag))
+            partNumber += 1
+            buffered = 0
+          }
 
-        val expectedParts = declaredLen
-          .map(ln =>
-            ((ln + partSize - 1) / partSize).toInt + 1
-          ) // “+1” for the last (possibly small) part
-          .getOrElse(MAXIMUM_NUM_OF_MULTIPART_S3_PARTS)
-
-        // ---------- ask LakeFS for presigned URLs ----------
-        val presign = LakeFSStorageClient
-          .initiatePresignedMultipartUploads(repoName, filePath, expectedParts)
-        uploadId = presign.getUploadId
-        val presignedUrls = presign.getPresignedUrls.asScala.iterator
-        physicalAddress = presign.getPhysicalAddress
-
-        // ---------- stream & upload parts ----------
-        /*
-        1. Reads the input stream in chunks of 'partSize' bytes by stacking them in a buffer
-        2. Uploads each chunk (part) using a presigned URL
-        3. Tracks each part number and ETag returned from S3
-        4. After all parts are uploaded, completes the multipart upload
-         */
-        val buf = new Array[Byte](partSize.toInt)
-        var buffered = 0
-        var partNumber = 1
-        val completedParts = ListBuffer[(Int, String)]()
-
-        @inline def flush(): Unit = {
-          if (buffered == 0) return
-          if (!presignedUrls.hasNext)
-            throw new WebApplicationException("Ran out of presigned part URLs – ask for more parts")
-
-          val etag = put(buf, buffered, presignedUrls.next(), partNumber)
-          completedParts += ((partNumber, etag))
-          partNumber += 1
-          buffered = 0
-        }
+          var read = fileStream.read(buf, buffered, buf.length - buffered)
+          while (read != -1) {
+            buffered += read
+            if (buffered == buf.length) flush() // buffer full
+            read = fileStream.read(buf, buffered, buf.length - buffered)
+          }
+          fileStream.close()
+          flush()
 
-        var read = fileStream.read(buf, buffered, buf.length - buffered)
-        while (read != -1) {
-          buffered += read
-          if (buffered == buf.length) flush() // buffer full
-          read = fileStream.read(buf, buffered, buf.length - buffered)
-        }
-        fileStream.close()
-        flush()
-
-        // ---------- complete upload ----------
-        LakeFSStorageClient.completePresignedMultipartUploads(
-          repoName,
-          filePath,
-          uploadId,
-          completedParts.toList,
-          physicalAddress
-        )
+          // ---------- complete upload ----------
+          LakeFSStorageClient.completePresignedMultipartUploads(
+            repoName,
+            filePath,
+            uploadId,
+            completedParts.toList,
+            physicalAddress
+          )
 
-        Response.ok(Map("message" -> s"Uploaded $filePath in ${completedParts.size} parts")).build()
+          Response.ok(Map("message" -> s"Uploaded $filePath in ${completedParts.size} parts")).build()
+        } else {
+          // Use single file upload method
+          LakeFSStorageClient.writeFileToRepo(repoName, filePath, fileStream)
+          fileStream.close()
+
+          Response.ok(Map("message" -> s"Uploaded $filePath using single upload")).build()
+        }
       }
     } catch {
       case e: Exception =>