How do I know which product metrics actually matter?

There are endless things you could measure, and it is easy to drown in dashboards while still not knowing whether the product is winning. If you feel lost about which numbers matter, that is not a gap in your intelligence. It is a sign you have not yet tied your metrics to what the product is actually for. The metrics that matter are the few that tell you whether you are delivering real value to users and to the business. Most numbers are noise dressed up as insight. The ones worth watching are those that would genuinely change your mind or your plan if they moved. Everything else you can safely ignore. So start by naming the one thing your product must do well for users, and find the single metric that best reflects it. Watch that one closely before adding any others. One number you truly understand and act on beats twenty you merely collect. Clarity comes from choosing, not from measuring everything.