Often, the single biggest drain on performance in a Go program is the garbage collector. Each release of the Go runtime comes with a slightly faster collector, but you can make much bigger performance improvements by not creating garbage in the first place: if you can rework your code to make fewer heap allocations, then the garbage collector will run less often and have less work to do.

Examples will be drawn from real-world experience optimising the Open Source container visualisation project Weave Cortex.