Disagreeing With Senior Engineers

The data team is designing a new service that records every price change on the marketplace's listings. A Staff engineer on the data team wants to store the history in Cassandra, a database that spreads rows across many machines and is designed for high write rates. The API Architect, who reviews the design, wants PostgreSQL, which the platform group already runs for many other services. Both are experienced and confident. Neither reports to the other.

In the first version of this story, the two engineers argue the answer directly. The design document collects 70 comments in three weeks