performance-engineering

Technology-neutral performance discipline - measuring before optimising, budgets and SLOs, profiling to find the real bottleneck (CPU, memory, IO, network, rendering), algorithmic complexity versus constant factors, caching and batching principles, latency percentiles, load testing basics, regression guards in CI, trade-offs against maintainability, avoiding premature optimisation, and writing up findings. Load when something is slow, when setting performance targets, when planning load tests, or when reviewing a change that claims a performance benefit.