Describe a time when you had to maintain high accuracy while entering a large volume of data under a tight deadline. What steps did you take to avoid errors and meet the deadline?

Last quarter I was responsible for entering 18,400 customer records into a new CRM in 48 hours to meet a go-live. I broke the work into 200-row batches, created a standardized import template, and built three validation rules in Excel to catch missing emails, invalid dates, and duplicate IDs. I used conditional formatting to flag anomalies and ran checksum totals after each batch. I also scheduled a 5% random spot-check each hour and paired with one colleague for a final peer review of every fifth batch. By automating address standardization and sticking to the batch/QA routine, we finished on time with a documented accuracy of 99.9% and reduced rework by about 75%.