Well say that you're building a micro service that needs to handle a high number of concurrent requests. A server running Go will handle ~100x the traffic of a Python or Ruby app. Your milage will vary depending on the use case, but the difference is huge.
Found out yesterday that even with async in Python someone can sneak in some sync code and totally ruin your day. All you know is your performance is plummeting all across your system and CPU is spiky as hell. Took me most of the day to realize the issue. From now on I’ll start every performance investigation with ‘grep requests’. Problems like this simply don’t exist in Go.
