Clarity is the cheapest work you will ever do. Ten minutes here saves a day of rebuilding.
Answer four questions: who uses this, what do they do first, what should never happen, and how will you know it worked.
Write the answers in plain language. No technical vocabulary is required or wanted at this stage.
If two answers contradict each other, you have found the real design decision. Make it now rather than halfway through.
Practice
Name one person who will use this and describe their first two minutes on the site.
Try this
Finish this sentence: 'This is working when ______ happens without me doing anything.'