Defining 'Low Latency': Why Being Fast Enough Matters More Than Being Fastest

Latency — the time between an event and its result — is a priority for most applications, but the right target depends heavily on the use case. For user-facing applications, responses in the 50–200 ms range are generally acceptable, and reducing latency below 50 ms rarely improves the user experience in a meaningful way. Backend systems, by contrast, must sustain processing speeds that consistently match or exceed the rate of incoming data, since no buffer can indefinitely compensate for a capacity shortfall. In competitive environments such as electronic trading, however, every microsecond counts and systems must aim to be among the absolute fastest to achieve the desired business outcome. The key takeaway is that 'low latency' is not a universal benchmark but a context-dependent threshold defined by what the business actually requires.