Best Practices for Enriching Company Info Without Duplicates

I have a test person table like that, what’s the best way to enrich company info and industry without duplicate enrichment for different people in the same company? I search the channel and yes we could create row number and only enrich first one among same company. But that way, at individual level we lose company info for people with row number > 1. One alternative solution I am thinking is wether we could create a separate table to extract the UNIQUE email domain and then do the enrichment. Then inside the people table, we do a row lookup to find the info we need. The problem is I cannot find a way to extract the UNIQUE email domain. “Write to table” does not work in this case since it requires a list in a single row whereas in our case it is multiple rows with same value. If my thought is not ideal, pls advice the best practice.