This is just not a great way to go about things and this is exactly the problem Agile is supposed be solving. When you deliver value incrementally, it becomes

This is just not a great way to go about things and this is exactly the problem Agile is supposed be solving. When you deliver value incrementally, it becomes painfully obvious to everyone where the gaps are and what's at risk of not being delivered. It also puts the onus on the customer to TELL you what they want instead of you having to guess. What a lot of young developers don't get is that you can't just solve every problem with deep analysis. Nobody gives a shit if you can find all the gaps in requirements because a day after you finish your analysis the requirements will change. There's requirements you need to define early. Who is using the system, expected availability, the different levels of access and the entities involved. Performance requirements, data security/tenancy requirements and some idea of how many users will be using the system concurrently are extremely important to understand up front. There are a ton of companies, particularly the ones that build custom software for public/private sector that are incredibly happy to have customers submit junk requirements and nickel and dime them on every single change request.