Agile Is an Exercise in Risk Management

At the end of the day, I insist that agile is essentially an exercise in risk management. And so maybe you just don't know what the memory requirements are going to be. Can't tell you it. Then your project plan needs to reflect that you need to try out the stuff that you know is going to be hugging memory early on. That's perfectly reasonable. It doesn't be nailing down every single last thing,. But being very keenly aware of the risks and dealing with them in the most productive way possible.