I could be misunderstanding your question, but the Sentry JS SDK sends exceptions to the server and they are unminified on the server side. The server will attempt to download the sourcemaps automatically, but you can also disable them in production and push them to Sentry manually (when you deploy). So this this gives you one existing option, and at least shows it's possible if you need a custom solution.
At Lucid (https://www.lucidchart.com), we've used a home-grown solution that stores the versioned source maps in S3, and decodes the stack traces server-side and adds it to the original trace in the logging system. Plus caching the decoding.
We've looked at Sentry and might use that. They offer hosted and open-source on-prem solutions.
Sweet. Sounds like what I am looking to do. Server side should be pretty straightforward. Is your client side code homegrown of do you use an OSS JS framework?
