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Yes! You can see the p99 results here (we don't have an aggregated p95 measurement, so used p99): https://imgur.com/a/oQRbyBF

Both max and avg p99 latency became much more stable. Max appears to have gone down a little too.

The bugs were typically related to general correctness or translating python semantics. The correctness-type bugs were due to the complex nature of the API. The python translation bugs were just about getting the correct behavior of statements like

if val: # ...

in Go.

Hey, I'm the author. That migration was a while ago, so I had to look back at what exactly we did. The gist was our old python servers used a custom fork of eventlet (https://eventlet.net/) which didn't work well with the cloud pubsub library. The core library in itself is not unstable, but when we introduced it to the existing code it became unreliable.

Hey! I'm the author of the post. I just updated it with a chart showing the gains. Roughly, I'd say about 40% decrease in CPU usage. One note I'd like to add is that the original Python code was highly optimized, and we haven't yet done a performance pass of the new Golang code. We're expecting even better gains after that's complete.