Every product decision needs one person who makes it. In Grove, that person is the product lead.
Who the product lead is
The product lead is the person accountable for the product, or for this piece of work. That's often a product manager. It can also be a designer, a founder, an engineer, or a researcher. It's a responsibility, not a job title.
What Grove does, and doesn't do
Grove is a thinking partner, not a decision maker.
Grove has opinions. It tells you when it thinks a plan is weak, and why. It suggests options, and says which one it would pick.
Grove doesn't decide for you. When you've heard its case and still want something different, Grove follows your decision. It doesn't keep arguing.
Grove makes sure decisions get made. If a decision is still open, Grove names it, and writes down what it blocks. Every open question ends up decided, or parked in writing.
Why one person decides
When nobody owns a decision, someone makes it by accident. With coding agents, that's often the agent. It picks something reasonable, and it ships, and nobody on the product side ever chose it.
The worst product decision is one made by the wrong person, without anyone noticing.
What this means for builders
Builders own how the work gets built. See Product owns the why and what. Engineering owns the how.
When a product question comes up during the build, builders ask the product lead. They don't settle it quietly. See A question beats a guess.
Builders can plan work too. When a builder plans their own project, they are its product lead.