Module developer_experience_metrics 

Developer Experience Metrics

Two practical measures from Part 3 of the book: focus time, the count and duration of uninterrupted two-hour-plus blocks per week (chapter 3.6’s efficiency-and-flow dimension), and survey response rate, itself a trust signal for a DevEx survey programme, not merely a data-collection statistic (chapter 3.7).

Formula

Focus block   = a calendar block >= 2.0 hours, uninterrupted
Response rate = (survey responses received / survey invitations sent) x 100%

Why it matters

Refocusing after an interruption to deep, complex work routinely takes many minutes, sometimes closer to half an hour, to fully rebuild the working memory an engineer was holding before the interruption. An engineer whose day is fragmented into short blocks may show plenty of activity while accomplishing far less genuinely difficult work than the same engineer would with two protected, uninterrupted hours. Separately, a declining survey response rate often indicates eroding trust in the process — survey fatigue, doubts that results lead to action, or suspicion that anonymity is not genuinely protected — and deserves direct investigation rather than being dismissed as a data-collection inconvenience.

Example

use software_engineering::developer_experience_metrics::{
    is_focus_block, response_rate_percent,
};

// "Uninterrupted blocks of two hours or more" count as focus time.
assert!(is_focus_block(2.0));
assert!(is_focus_block(2.5));
assert!(!is_focus_block(1.75));

// A DevEx survey sent to 100 engineers, 72 responses: 72% response rate.
assert_eq!(response_rate_percent(72.0, 100.0), Some(72.0));

Pitfalls

• Using interruption or notification data as individual surveillance repeats the misuse risk the book warns against for activity data; aggregate at the team level.
• Imposing a single, rigid focus-time schedule on everyone ignores genuine individual variation in how people work best.
• Ignoring a declining response rate misses an important trust signal in its own right — investigate rather than dismiss it.

Sources

• Chapter 3.6, Efficiency and flow: deep work and interruptions.
• Chapter 3.7, Developer experience surveys and DevEx metrics.

Topic doc: software-engineering-metrics/locales/en-001/chapters/03-06-efficiency-and-flow.md Topic doc: software-engineering-metrics/locales/en-001/chapters/03-07-developer-experience-surveys-and-devex-metrics.md

Functions

is_focus_block

Whether a calendar block qualifies as protected “focus time”.

response_rate_percent

Survey response rate as a percentage: responses received / invitations sent x 100.