Make the client web page attractive by styling it using CSS.
Configure a CloudFront CDN to compress and locally cache static assets, then reconfigure the application so users access it through the CDN.
The error handling in this chapter only acts on problems during file uploads, not on problems during file conversion. Using the dead-letter queue technique from Chapter 9, detect conversion errors and save a marker error file somewhere on S3 where the client can detect it. Then change the client-side workflow to poll for that file while waiting on results and notify clients about conversion errors.
In the next lesson, you have a short quiz, so buckle up!