I'd be up to it if we manage to cram it up in a following sprint and it is worth it.
We could run a controlled test against production with a long batch of articles and check median/percentiles response time with repeated runs and highlight the different results for human inspection regarding quality.
It's been noted previously that the results are far from ideal (which they are because it is just morelike), and I think it would be a great idea to change the endpoint to a specific one that is smarter and has some cache (we could do much more to get relevant results besides text similarity, take into account links, or see also links if there are, etc...).
As a note, in mobile web the related articles extension allows editors to specify articles to show in the section, which would avoid queries to cirrussearch if it was more used (once rolled into stable I guess).
I'm not sure if we ended up adding the smaxage parameter (
I think we didn't), should we? To me it seems a no-brainer that we should be caching this results in varnish since they don't need to be completely up to date for this use case.