diff --git a/storage/storage.go b/storage/storage.go
index f6728b8..d3230bd 100644
--- a/storage/storage.go
+++ b/storage/storage.go
@@ -5,7 +5,13 @@ import (
 	"context"
 	"fmt"
 	"io"
+	"math"
 	"net/http"
+	"sort"
+
+	"github.com/aws/aws-sdk-go-v2/service/s3/types"
+
+	"github.com/docker/go-units"
 
 	"github.com/aws/aws-sdk-go-v2/aws"
 
@@ -31,6 +37,8 @@ import (
 )
 
 const PROOF_EXTENSION = ".obao"
+const S3_MULTIPART_MAX_PARTS = 9500
+const S3_MULTIPART_MIN_PART_SIZE = uint64(5 * units.MiB)
 
 var _ StorageService = (*StorageServiceDefault)(nil)
 
@@ -59,6 +67,7 @@ type StorageService interface {
 	DeleteObject(ctx context.Context, protocol StorageProtocol, objectHash []byte) error
 	DeleteObjectProof(ctx context.Context, protocol StorageProtocol, objectHash []byte) error
 	S3Client(ctx context.Context) (*s3.Client, error)
+	S3MultipartUpload(ctx context.Context, data io.ReadCloser, bucket, key string, size uint64) error
 }
 
 type StorageServiceDefault struct {
@@ -319,7 +328,82 @@ func (s StorageServiceDefault) S3Client(ctx context.Context) (*s3.Client, error)
 	}
 
 	return s3.NewFromConfig(cfg), nil
+}
 
+func (s StorageServiceDefault) S3MultipartUpload(ctx context.Context, data io.ReadCloser, bucket, key string, size uint64) error {
+	client, err := s.S3Client(ctx)
+	if err != nil {
+		return err
+	}
+
+	mu, err := client.CreateMultipartUpload(ctx, &s3.CreateMultipartUploadInput{
+		Bucket: aws.String(bucket),
+		Key:    aws.String(key),
+	})
+	if err != nil {
+		return err
+	}
+
+	partSize := S3_MULTIPART_MIN_PART_SIZE
+	totalParts := int(math.Ceil(float64(size) / float64(partSize)))
+	if totalParts > S3_MULTIPART_MAX_PARTS {
+		partSize = size / S3_MULTIPART_MAX_PARTS
+		totalParts = S3_MULTIPART_MAX_PARTS
+	}
+
+	var completedParts []types.CompletedPart
+
+	for partNum := 1; partNum <= totalParts; partNum++ {
+		partData := make([]byte, partSize)
+		readSize, err := data.Read(partData)
+		if err != nil && err != io.EOF {
+			return err
+		}
+
+		uploadPartOutput, err := client.UploadPart(ctx, &s3.UploadPartInput{
+			Bucket:     aws.String(bucket),
+			Key:        aws.String(key),
+			PartNumber: aws.Int32(int32(partNum)),
+			UploadId:   mu.UploadId,
+			Body:       bytes.NewReader(partData[:readSize]),
+		})
+		if err != nil {
+			// Abort the multipart upload in case of error
+			_, abortErr := client.AbortMultipartUpload(ctx, &s3.AbortMultipartUploadInput{
+				Bucket:   aws.String(bucket),
+				Key:      aws.String(key),
+				UploadId: mu.UploadId,
+			})
+			if abortErr != nil {
+				s.logger.Error("error aborting multipart upload", zap.Error(abortErr))
+			}
+			return err
+		}
+
+		completedParts = append(completedParts, types.CompletedPart{
+			ETag:       uploadPartOutput.ETag,
+			PartNumber: aws.Int32(int32(partNum)),
+		})
+	}
+
+	// Ensure parts are ordered by part number before completing the upload
+	sort.Slice(completedParts, func(i, j int) bool {
+		return *completedParts[i].PartNumber < *completedParts[j].PartNumber
+	})
+
+	_, err = client.CompleteMultipartUpload(ctx, &s3.CompleteMultipartUploadInput{
+		Bucket:   aws.String(bucket),
+		Key:      aws.String(key),
+		UploadId: mu.UploadId,
+		MultipartUpload: &types.CompletedMultipartUpload{
+			Parts: completedParts,
+		},
+	})
+	if err != nil {
+		return err
+	}
+
+	return nil
 }
 
 func (s StorageServiceDefault) getProofPath(protocol StorageProtocol, objectHash []byte) string {