latency budget
also: performance budget, time budget, response time budget
The maximum acceptable delay or response time allocated for a specific operation or system component within a larger application or workflow. It represents a time constraint that must not be exceeded to maintain performance requirements.
A latency budget is a predetermined time limit for how long an operation is allowed to take before it negatively impacts user experience or system performance. It's often expressed in milliseconds and serves as a target for optimization and monitoring.
For example, a web application might allocate a 200ms latency budget for a database query—meaning the query must complete within that time frame. If the query takes longer, the application exceeds its budget and may trigger performance alerts, caching strategies, or timeout fallbacks.
Latency budgets are particularly important in real-time systems, interactive applications, and microservices architectures. Developers distribute the total acceptable latency across multiple components (network calls, processing, I/O) to ensure the overall system meets performance goals. Monitoring tools track whether operations stay within their assigned budgets.