Project ended up saving 10x that per year, so wasn't a huge deal. Quickly rewrote it to run as a traditional server, though.

nah I was using it for benchmarking downstream services and the benchmark "worked" in that it overloaded the downstream services and accidentally had the lambas waiting too long for responses (we had to wait, to simulate real load and connections).

It was originally estimated like 10k or something per test which was approved at the time (had like 3 level of management all down my neck for getting it out, hence using lambda originally).

We did deliver, just needed one more sprint to rewrite it as a distributed system on servers. ;) Moved to like 20 machines w/ 128gb of ram that we could spin up as needed (testing millions of events a second, system in NodeJS!)