I worked at a shop that had to process about 6M RPS for 5 seconds at a time, once a minute or so. That looked a lot like a boatload of Python background threads

I worked at a shop that had to process about 6M RPS for 5 seconds at a time, once a minute or so. That looked a lot like a boatload of Python background threads queueing work in memory then flushing them out into Cassandra. That was a fun little project.