Q:

AWS Static web hosting - tedious to update site

I'm using AWS to host a static website. Unfortunately, it's very tedious to upload the directory to S3. Is there any way to streamline the process?

A:

Have you considered using AWSCLI - AWS Command Line Interface to interact with AWS Services & resources.
Once you install and configure the AWSCLI; to update the site all that you need to do is 

aws s3 sync s3://my-website-bucket /local/dev/site

This way you can continue developing the static site locally and a simple aws s3 sync command line call would automatically look at the files which have changed since the last sync and automatically uploads to S3 without any mess. 
To make the newly created object public (if not done using Bucket Policy)

aws s3 sync s3://my-website-bucket /local/dev/site --acl public-read

The best part is, the multipart upload is built in. Additionally you sync back from S3 to local (the reverse)

