The DB schema in RDS is identical to the DB schema on a Postgres server in your data center and the RDS data dumps can be loaded into your very own personal DB

The DB schema in RDS is identical to the DB schema on a Postgres server in your data center and the RDS data dumps can be loaded into your very own personal DB wherever you like. The dockerfile used to build the containers in ECS can be pushed to any registry and the resulting containers can run on any docker service. What vendor lock in? I just don't buy that argument. Use the services Luke ;) it will cost much less and you can focus on other things!