One-way doors

You can edit a file, hate the result, and git checkout your way back to before. You cannot un-send an email. You cannot un-push a force-push that someone else already pulled. You cannot un-drop a database table.

A one-way door is an action you can’t easily undo. Once it’s through, it’s through.

The phrase comes from a memo by Jeff Bezos about decision-making: two-way doors you can walk back through; one-way doors close behind you. The framing is even more useful for shell commands than for company strategy.

What goes through which door

Two-way (reversible, take your time but don’t agonize):

• Editing a file. Git holds the old version.
• Creating a file or folder. Delete it later if you don’t want it.
• Running a build, a test, a linter. Output, no permanent change.
• Installing a package. You can uninstall it.

One-way (slow down, read twice):

• Sending — email, Slack, webhook, anything to another person or system.
• Pushing to a branch other people use, especially --force.
• Deleting things that aren’t in git yet, or that git doesn’t track.
• Dropping or truncating database tables.
• Anything that costs money — paid API calls, cloud resources spun up.
• Anything that crosses the network into someone else’s system.

The one question

Before approving anything that doesn’t feel like a plain file edit, ask:

If this turns out to be wrong, can I take it back?

If yes, click through and move on — speed is fine in a hallway full of two-way doors. If no, slow down. Read what it’s about to do. Maybe ask Claude to explain why it’s doing it that way. Maybe paste the proposed command back and ask if there’s a safer version.

This single question catches almost every “oh no” moment you’ve ever heard a developer tell a story about.

Blast radius vs. one-way

Easy to confuse the two. They sort prompts differently:

• Blast radius = how much could be affected.
• One-way-ness = whether you can get it back.

A test that fails has zero blast radius and is fully reversible. Deleting your only copy of an unsaved file has small blast radius (one file) but is fully one-way. The two questions stack — both worth asking.

What’s next

You can now read a prompt and judge its danger. Time to learn the other lever you have: not whether to approve a single prompt, but the mode you’re working in.