Glossary
What is Deep Work?
Short answer
Deep work is professional activity performed in a state of distraction-free concentration that pushes cognitive capabilities to their limit. The term was popularized by Cal Newport in his 2016 book of the same name.
Full definition
Deep work contrasts with 'shallow work' — non-cognitively demanding, logistical tasks like email. It requires sustained attention, typically 60–90 minute blocks, with minimal switching. Research shows that each interruption costs roughly 23 minutes of re-focus time, which is why single-purpose tools (like IdleMac) that protect a block of attention outperform multi-purpose dashboards.
Cal Newport's interview-based research suggests 4 hours/day of deep work is the practical ceiling for most people.
Examples
- Writing a technical design doc with Slack and email closed.
- Coding a complex feature with notifications muted.
- Solving a hard proof without checking your phone.