concurrency-limits VS souin

Does anyone know if there's a reputable OS load shedding / concurrency limiting package similar to Netflix's concurrency limits Netflix/concurrency-limits (github.com) for NodeJS? I'm migrating some middleware written in Kotlin to NodeJS and wanted to know how folks typically solve this problem.

Under heavy congestion the goodput (useful throughput) will drop to 0 because client will start timing-out before the server get a chance to respond.

Caddy should use an algorithm similar to : https://github.com/Netflix/concurrency-limits

Basically check what was the best request latency, and decrease concurrency limit until latency stop improving.

https://github.com/Netflix/concurrency-limits

FWIW envoy also has an adaptive concurrency experimental plugin that seems similar that I'd also love to hear about any real world experience with:

HTTP plugin now support RFC 7234 caching options

It's always been blisteringly fast when we've used it, and I like the power of the configuration (it has its quirks but so do most powerful systems). But the overhead of setting it up and maintaining it due to having to handle TLS termination separately puts me off using it when other software is 'good enough'. If Varnish Enterprise was cheaper I would have bought it, but at their enterprise prices no way.

I'm keeping a watching brief on https://github.com/darkweak/souin and its Caddy integration to see if that can step up and replace Varnish for short-lived dynamic caching of web applications. Though I've lost track of its current status.

Centminmod (need lots of tweaks) or OpenLiteSpeed are consider more performant than default Nginx and Caddy, but I wish if someone can prove there is a better one out there or I just saw Souin HTTP cache (https://github.com/darkweak/souin) when I was reading Echo web framework for Go. Yet to experiment if there is a benefits unless it's insignificant.