A PM's influence comes almost entirely from trust and clear communication, since a PM typically has no direct authority over designers or engineers. When reviewing a design, effective feedback focuses on whether the user's problem is solved and on specific friction points ("I'm not sure the new user would know this button does X"), rather than personal taste ("I don't love this color") or redesigning the screen yourself. In technical discussions, a PM doesn't need to write code, but does need enough technical literacy to understand trade-offs, for example, that a "quick fix" might create technical debt (shortcuts that create more work later) while a more thorough approach takes longer now but avoids future rework, and to help the team decide which trade-off fits the current priority.