[wlll]

The place I work (CTO for now, looking for opportunities pretty soon) can sustain nearly 400 RPS through a Rails app on a single Performance-L Heroku dyno without a sweat (though we run two min), but it's the tip of the iceberg. The infra to support those web servers is way more than that. Aurora Postgres x 3 for now, a large ES cluster, 2x redis clusters, memcached etc.

Bear in mind that we had I think 6 apps. Basecamp 1, 2 and 3 (all separate infra), Highrise, Campfire, some other internal stuff. Our ES cluster was pretty damn big, redis and memcached too. Juniper, F5, network switches (rack infra) etc. Storage was pretty big, quite a few 4u servers with spinning rust. The blade servers were I think 6 blades in 2u.

Everything was redundant, everything had 2x or more. I honestly can't remember how many racks we had. "More than 10" is my hand-wavey guess.

I don't think DHH was being disingenuous with his "2k on 30 servers" message, it was likely more about the scalability of Rails rather than the infra required to run the app.