Decision-making and strategy
One-way and two-way doors
Make reversible decisions quickly and save slow, careful deliberation for the ones you cannot undo.
Jeff Bezos, 2015 letter to Amazon shareholders.
Bezos split decisions into two types. Type 1 decisions are consequential and irreversible or nearly so: one-way doors. They deserve method, care and consultation. Most decisions are Type 2: changeable and reversible. If you walk through a two-way door and dislike the room, you walk back. He wrote that these should be made quickly by people with good judgement or small groups.
The point is that the cost of being wrong depends on whether you can recover. A reversible mistake costs a little time. Treating every decision as permanent buys safety you do not need and pays for it in speed. Bezos warned that large organisations drift into using the heavyweight process for everything, which leads to slowness, unthoughtful risk aversion and too little experimentation.
The hard part is classifying correctly. Some doors look two-way and are not: data deletion, public statements, a hire, a database schema that other teams start depending on. Others look one-way only because nobody built a rollback. Often the best move is to turn a one-way door into a two-way one first.
Example
On 31 January 2017 a GitLab engineer, trying to resynchronise a replica, ran a command to wipe the PostgreSQL data directory on the secondary database server. It ran on the primary instead. The regular backups turned out to have been failing silently, so the team restored from a snapshot taken about six hours earlier. GitLab's postmortem estimated that data for at least 5,000 projects, 5,000 comments and roughly 700 users was lost.
Where it applies
Ship features behind flags, prompt changes behind versioned configs, and model upgrades behind gradual rollouts, so most decisions become two-way doors. Keep the slow review for migrations, deletions, public commitments and anything touching user data.
Think about it
Which decision are you stuck on that you could actually reverse next month if it turns out wrong?
Applied it to something real? Log it.
Test yourselfHow should the reversibility of a decision change how you make it?
Reversible (two-way door) decisions should be made quickly by a person or small group. Irreversible (one-way door) decisions deserve slow, careful deliberation.
Related models
- Second-order thinkingKeep asking "and then what?" until you have looked at the consequences of the consequences.
- Circle of competenceKnow where your real understanding ends, and keep your big bets inside that line.
- OptionalityPrefer positions that give you the right, but not the duty, to act later, so you can take the upside when it appears and walk away when it does not.
- Regret minimizationFor a big personal choice, imagine yourself at 80 looking back, and pick the option you would be least likely to regret.
- The sunk cost fallacyMoney, time or effort already spent cannot be recovered, so it should not count in what you do next; people count it anyway.