Low Latency?
In computing, latency is defined as the length of time to perform some task. This could be the time it takes to respond to an interrupt from hardware or the time it takes for a message sent by one component to be available to its recipient.
In many cases, latency is not seen as a primary non-functional concern when designing an application, even when considering performance. Most of the time, after all, computers seem to do their work at speeds that are well beyond human perception, typically using scales of milliseconds, microseconds, or even nanoseconds. The focus is often more on throughput - a measure of how many events can be handled within a given time period. However, basic arithmetic tells us that if a service can handle an event with low latency (for example, microseconds), then it will be able to handle far more events within a given time period, say 1 second, than a service with millisecond event handling latency. This can allow us to avoid, in many cases, the need to implement horizontal scaling (starting new instances) of a service, a strategy that introduces significant complexity into an application and may not even be possible for some workloads.