50,000 requests in the span of ... 21 days? It might be interesting if it were 50 million in those 21 days (even then, 27 RPS is ... nothing). Drop a report to AWS T&S, block, drop, reject, and move on. This is like less than background noise at this point.

Edit: tamping down a bit of my prickliness because it looks like this individual is a relative newcomer to running internet-facing services. This is actually a pretty good intro to that: the place as a whole is a cesspool and any conceivable “attack”, scan, probe, pentest is, has, or will be happening at all times. Some you can mitigate yourself, others you’ll need to bring in a specialist service (see DDoS sinks and mitigation services, for example) or contact someone’s abuse address, others you just have to ignore because it’s just not directed at you personally, or just not worth more than three seconds’ thought beyond a firewall rule. This is the latter. Maybe interesting if this is the first time you’re seeing something like this, but for more grizzled operators like myself, it doesn’t even register as notable anymore.