[wnmurphy]

This is actually really simple to solve: product articulates the problem, engineering designs the solution.

When product tries to design the solution, tosses it over the fence, and engineers who don't know any better just implement it, you end up with a codebase that consists of parts duct-taped onto the side of other parts. Over time this compounds the cost of future development.

When you let engineering design the solution, they design for reuse, with the lightest touch. This decreases the cost of future development by keeping the codebase maintainable, understandable, unsurprising, simple, etc.

If your user stories from product contain implementation details, you need to guide the discussion back to the actual problem that needs to be solved.

[fmbb]

Not only is this easy to solve, Scrum is one solution. Like this is the core of what it attempts to solve.