Build a learnings log so the system never relearns a lesson

Build a learnings log so the system never relearns a lesson

Individual experiments are forgettable. The compounding asset is the body of everything you have learned, held somewhere durable, so the team's knowledge of its buyers and funnel grows test by test instead of resetting every time someone leaves or the quarter turns. Without that log, you are not running a learning system, you are running the same few experiments on a loop with new faces.

The log is simple and it earns its keep immediately. One entry per experiment: the hypothesis, the change, the metric, the pre-set threshold, the result, the decision, and one line on what it taught you about the buyer. That is it. The discipline is not the format, it is that every experiment closes with an entry, no exceptions, so the log is a complete record rather than a flattering highlight reel of the wins.

A real log changes the front of the funnel of ideas. New experiment proposals get checked against it first: have we tested something like this, what did we learn, does this contradict a result we already trust? That single habit stops the most expensive waste in growth, which is re-running a settled question because nobody remembered the answer. The log turns past tests into a filter on future ones.

The log is also what makes the system portable. A growth programme whose knowledge lives in one person's head dies when that person is busy, distracted, or gone. A programme whose knowledge lives in a readable log can be picked up by anyone, including the version of you six months from now who has forgotten the details. If a new operator could read your log and know what your buyers respond to, you have built a system. If they could not, you have built a habit.

Make capturing the lesson part of the work, not an extra chore bolted on at the end. The entry gets written when the experiment closes, in the same session you make the ship-or-kill call, because that is the only moment the context is fresh and the motivation exists. Anything you leave for "later" in a busy growth team is a lesson you have decided to lose.

INTERVIEW EWOUD: Show me what your experiment learnings log actually looks like, and tell me about a time it stopped you from re-running a test you had already answered. What was in the entry that saved the work?