NFR: Latency

Ensure low end-to-end latency from hot-key activation to text injection.

Requirement

• 95th percentile time-to-text ≤ 3 s for a 5-second audio clip on Apple Silicon (M1) using the
• small Whisper model.
• Latency measured in release (optimised) builds with all background services running.

Rationale

Sub-3-second latency preserves conversational flow and competitive advantage over cloud dictation.

Acceptance Criteria

• Automated telemetry logs latency for every invocation.
• CI latency test passes on GitHub Actions M1 runner.
• Performance regression test fails build if P95 > 3 s.

Test-Driven Design

Create automated performance tests that measure P95 latency; commit them before optimising the code.

References

PRD §7 Non-Functional Requirements – Latency