Database migrations at scale are rarely clean.
@Netflix had nearly 400
#PostgreSQL clusters to move and doing it manually was never an option. So they built a self-service automated workflow instead. This is a really interesting read!
The approach uses
#Aurora read replicas for near-zero downtime, with traffic cutover handled through their Data Access Layer rather than application code changes. Replication lag, WAL validation, and CDC handling were all covered.
This writeup from Ram Srivasta Kannan, Wale Akintayo, Jay Bharadwaj, John Crimmins, Shengwei Wang, and Zhitao Zhu is worth a read if you manage databases at any meaningful scale. Check it out!