The C10K problem may seem like a relic today, but the call to action was symptomatic of the type of approaches to systems' applications that were primarily employed prior to the rapid expansion of concurrent languages and application design.

Just 15 years ago, this seemed a largely insurmountable problem facing systems and server developers worldwide; now, it's handled with only minor tweaking and consideration by a server designer.

Go makes it easy to get there (with a little effort), but reaching 10,000 (or 100,000 or even 1,000,000) concurrent connections is only half the battle. We must know what to do when problems arise, how to seek out maximum performance and responsiveness out of our servers, and how to structure our external dependencies such that they do not create roadblocks.

In our next chapter, we'll look at squeezing even more performance out of our concurrent applications by testing some distributed computing patterns and best utilizing memory management.