Comparison
ReversibilityvsTwo-way door
Reversibility
you shipped it because you knew exactly how you would undo it, not because you were sure.
How cheaply a change can be undone, treated as a design property in its own right. It is what lets a team move fast without being reckless: high reversibility means being wrong is survivable, so decisions can be made with less information. Most of modern delivery practice — flags, canaries, small batches, backward-compatible migrations — is the pursuit of this one property, and framing it that way makes the practices arguable rather than ceremonial.
Full entry →Two-way door
you argued for a week about a library you could have swapped out in an afternoon.
A decision you can walk back cheaply if it turns out wrong. Most decisions are these, and treating them as if they were not is the most common way engineering organisations become slow. The correct handling is to decide quickly, at the lowest sensible level, and spend the saved deliberation on the small number of decisions that are actually one-way.
Full entry →