Answer:
Assuming you are using the AWS CLI to upload data to s3, there are two optimizations to increase the speed:
1) Parallel chunked uploading, which uploads your (large) file in chunks in parallel.
2) use Amazon S3 Transfer Acceleration
This will upload your file to a nearby CloudFront instance
You can enable this in your CLI configuration file, named config in the .aws folder. Add the following lines:
s3 =
 max_concurrent_requests = 20
 max_queue_size = 10000
 multipart_threshold = 64MB
 multipart_chunksize = 16MB
 max_bandwidth = 100MB/s
 use_accelerate_endpoint = true
 addressing_style = path