Gloria Mark

Foreword

By Edo Segal

The metric I trust least is the one I check most often.

Lines of code shipped. Features deployed. Sprint velocity. The dashboard that tells me my team is performing. I have built my career around these numbers. I have hired and fired based on them. I have stood in front of boards and pointed at graphs climbing upward and felt the specific warmth of vindication that comes from visible, measurable progress.

Gloria Mark spent twenty years measuring something those dashboards never show. She measured what happens inside the mind of the person producing the output. Not what they build. Not how fast. What it costs them — cognitively, attentionally, neurologically — to build at the pace the dashboard rewards.

The number that unsettled me was not a productivity figure.