[bjackman]

You don't save memory with code, you save it with architecture, platform decisions, and feedback loops.

Feedback loops are the important bit. If you want to reduce your service's memory footprint, don't at the code look at the memory profile and monitoring. You will find something like "oh shit 30% of our RAM is used by these buffers that we could basically eliminate if we tweak the flush frequency".

If you automate/regularise those investigations you will get an efficient service.

Same is true of every other performance metric, and reliability. It comes from your engineering processes (alerts, qualification, prod experimentation) not "write better code".