Cal Newport's concept of deep work rests on a simple but demanding idea: meaningful cognitive output requires long, uninterrupted stretches of concentration, and that state takes time to enter and almost no time to break. A single Slack notification, a reflexive tab switch, or a Discord ping doesn't just cost you the thirty seconds of the interruption — it costs you the ten or fifteen minutes it takes to get back into flow afterward.
This is why deep work is so hard to protect casually. It's not that people lack the two hours; it's that the two hours get sliced into six twenty-minute fragments by things that felt harmless in the moment.
What a Deep Work Block Actually Requires
Protecting a deep work session means removing every plausible interruption before it starts, not reacting to interruptions as they come. That means the communication apps are unreachable, the news and social sites are unreachable, and there's no easy toggle to check "just one thing" halfway through. The barrier has to exist before the temptation does.
Building the Block on Mac
Lock In! is built for exactly this — start a session and both distracting websites and distracting apps are blocked for its duration, system-wide.
Set the Block Before You Start Working
Configure a blocklist covering communication apps, social sites, and anything else that tends to pull you out of flow. Start the session before you open your actual work, so there's no window where a distraction could slip in before the block is live.
Pomodoro for Structured Deep Work Blocks
If two unbroken hours feels daunting, Pomodoro intervals break deep work into 25-minute sprints with short breaks — long enough to enter flow, short enough to sustain across a full day without burning out.
Strict Mode for the Sessions That Matter Most
For the work that genuinely needs protection — a deadline, a hard problem — Strict Mode makes the session uncancellable. There's no click-to-disable moment when the first hard sentence of the day shows up.
Full-Screen App Blocking Covers the Desktop, Not Just the Browser
Deep work interruptions don't only come from the browser. Slack, Discord, and Messages notifications on the desktop are just as disruptive, and Lock In! blocks those with a full-screen interrupt rather than leaving them for a website blocker to miss entirely.
Two protected hours beat six fragmented ones. Get Lock In! on the Mac App Store