The problem with caching
Now got new problem: updating the S3 bucket isn't updating the site. Of course it's because the bloody Cloudfront distribution is still serving the old files - because it caches a response from S3 for 24 hours, so if I update my site within that timeframe, it's not going to show.
me caching my tears - HAH dat pun.
Praise the internet gods for Stack Overflow, which then led me here to AWS docs. Apparently the free tier is up to a 1000 invalidations a month which is plenty.