Your question is Sample Size for A/B Test. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
How do you determine the sample size for an A/B test?
Explain the inputs and assumptions you need, including the baseline metric, minimum detectable effect, significance level, statistical power, variance, and allocation. Show how you would translate the required sample into experiment duration, and mention how your analysis plan accounts for guardrails, repeated peeking, and the unit of randomization.