How do you pushback on different feature ideas from internal or external stakeholders?

This is an art and a science. We have a process where we use technology advisory groups - combinations of people across different functions - to collect inputs and use a platform to capture suggestions, ideas, and feedback. We sort it out at a regional level and review it on a regular basis. We prioritize based on level of impact across the customer base, considerations of revenue, how much this would serve the market, etc. Combine, review, prioritize, and argue - it takes a handful of hours on a monthly basis, and during the quarter, we’ll swap in and out priorities depending on what’s going on.

Define a clear vision for the year (or longer) through an agreed upon charter that outlines a scope. Features additions should be tied back to downstream processes and value generation. If you cannot quantify or qualify the value a new feature can generate, its most like a "want" instead of a "need". 

Having a clear set of initiatives for the year (a sizeable long-term plan) has helped. If ideas come up that are outside of what the focus is, I push back by saying that isn't what we are focusing on now and back that up by sharing a clear plan.